Scary Cat

[copie]

Well hi to you all. I have a friend/associate with a near new 6 mt kevlar cat, twin 140 hp suzuki 4 strokes. He has previously owned mono hull boats. Travelling out to his fishing destinations he appears to be happy with the new boat, BUT when it's time to come home so running with a following sea he say's the handling is frightening to say the least. In fact a coment was white knucklesfrom all on board. It appears the new cat can comfortably run out or head on at reasonable speeds and handles it well. When running with the sea he backs right off to approx. 12knts.His complaint is the boat appears to dive nose down with a lean to his side (driver side) down the face of a swell or wave with the apparent feeling that it wont come back up. The boat was returned to the manufacturer for inspection and they checked inspected and even ex-rayed the right side hull in case it was filling with water. they apparently found nothing wrong and returned the boat to the owner. The boat still reacts in the same maner. I personally have never owned a cat but thought some of you cat owners and in particular kevlar cat owners could offer some assistance. Oh it's apparent handling vice is so that he wont take his family out in the boat in any weather as it frightens them all.
I THANK ALL IN ADVANCE FOR ANY ADVICE MARK.:o

[Dean1]

Cats are known to dig a hull in occasionally whilst in a following sea but always normally push through it. Is he triming the motors up?? Sounds like he has the motors trimmed down and if this is the case he would be experiencing a shocking ride. Get that nose up...

[mirage]

Seems to be a common problem with new cat owners untill they learn a cat's characteristics. There is another thread on here with exactly the same comments from a newly purchased KC 2400.

[snelly1971]

I know what you mate is going through...been there done that...and it is a hard thing to get used to...I mean ..It takes time to learn to drive a cat...and I think you never stop picking up little points about them..no matter how good or long you have driven them for...

He definatly needs more trim...and tell him no to be too scared to poke it into her a bit more...

Cheers Mick

[Dan5]

thats called the cat corkscrew twist it feels unerving for a while but you will get used of it i used to drive a 42 noosa cat on day charter very safe passed all stabilty tests for survey no worries.Quartering usually FEELS worse keep the power on motors slight trim up it will wander slightly up front but always come back,try hand steering for awhile till you get used of it before using the auto so you get the feel of her.Kevlacat do alot of homework before they punch out a hull so its not poor design your just used of your mono thats all.

[finding_time]

I've had the first my first cat now for about 3months( 5.2 kevlacat) and there are plenty of things that take awhile to get used to The main 1 is the way the boat reacts in a following sea and for a while it was freeky but am slowly getting used t the whole senario.

I would not back the boat of to 12 knots i reckon your asking for problems , everything i have been told is the harder you run them the better they go, and this appears to be true. I trim the boat out as far as i can then ajust one in to get the boat level , point in the direction i want to go and hit the throttle, then you have to do the hard part ( For people used to mono's) TRUST THE HULLS!! to work as they should, sometimes the down swell hull digs abit and then i power this engine a bit more and drive the hull through it, i imagine that the worst thing you could do i back that engine off as that hull needs the power to work properly. Yes you lean into the holes sometimes but it seems to come back,it's just very very differant to what your used to. In a mono you would steer away from the hole there by leveling the boat, do this in a cat and it will lean more into the hole, doh. To me it's getting easier to drive if i just stick to these 3 rules

1. point where i want to go and head straight for it , dont drive the boat like you would a mono, ducking and weaving is bad

2' drive hard , speed is your friend

3. sit back , relax and enjoy the ride

Ian

As i said i'm only very new to cat driving and some of the more experienced hopefully will give there advice

[Reel Magic]

I know nothing but Ian sounds like he knows what he is talking about, if all else fails contact kittycat.

He works at Springwood Marine and is a member here, may sound biased but he owns one so I am sure he can offer some words of wisdom.

Cheers Ryan.

[finding_time]

Where'sthe boat based? He should get a salesman or someone from kevlacat to take him out when the weather is pretty bad put the boat through it's paces with a experienced driver so he has confidence that it wont do anything strange when he's driving

Ian

[hungry6]

Copie, best bit of advice I can give is to ask an experienced cat owner to come out and steer it whilst your friend looks on, I remember my first ride in a cat after years of mono hull, I literally CR*P my self when we came of a swell at decent speed and the right hull dug in, the nutter behind the wheel is a member of this forum and have vast cat handling just powered her through it and she came up, Even now i still feels uneasy at times "hard to kick old habits" but always remember to steer and power into the lean, and use the trim!!!
Also, I found that every cat has a sweet cruising"speed" and this is where your friend should find and make the most of it for comfort and economy.
Plenty of cat owners on here, some are shy, most of them are pretty helpful just need them to post and expand the knowledge for other cats owners.
I would never look at another monohull period! now that I have looked on both side of the fence.

[PinHead]

a cat is very different to a mono to drive..I have limited experience in driving a cat...have been out with a very experienced cat skipper...his hand was working the throttles almost constantly...brilliant to watch him handle the cat...it did feel strange at times but he just kept it going ...very impressive when in the hands of an experienced skipper...just takes practice and experience...before i bought my current boat I was looking at a markahm 7m cat but decided against it...would be too impatient to acquire the skills to handle it properly.

[Kerry]

It's called take your time and become acquainted with the boat.

However based on some of the comments do not go to the extreme or push things too far at this stage and not expect to come unstuck thinking the boat will do all the looking after you, it might not.

Regards, Kerry.

[Blackened]

G'day

Like all have said before, you friend will need to shake off old mono habits and re-learn driving a cat.

Pete - Grand_Marlin put up a brilliant reply on one of the biggish threads on how to drive one properly . I'm not sure where it is now, but it is around :)

I always say, once you go cat you never go back

Dave

[Dean1]

But theres always someone stupid like me who had a cat and went back to a plate aluminium, VERY BAD MOVE!!! :-[ Im presently looking for a cat and the platey will be up for sale shortly.. Cant wait to get back in a cat, cant beat em ;D

[finding_time]

It's called take your time and become acquainted with the boat.

However based on some of the comments do not go to the extreme or push things too far at this stage and not expect to come unstuck thinking the boat will do all the looking after you, it might not.

Regards, Kerry.

A little less criptic please Kerry, you seem to no the cats very well if your going to give advice how about tryng to make it a little more constructive.

I feel my runs much better at 24knots than the 19 i was first trying to run it at. I assume you agree with this. I also find that if the down hill hull digs in abit if i power that hull it pushes through the hole, is this wrong shoud i just let the throttles be? I again assume that running down hill i'm trimmed out as far as i can,then use just one of the motors to keep it balanced,is this what you would do? What about the driving ,is point and shoot right? i know that trying to turn away from the digging hull would be bad, is turning towards it a better thing to do?


These are questions i've spent a bit of time thinking about and i'm only new to the cat driving senario, so i'm sure that answers to these would really help Marks friend;)

[troy]

Findingtime,
If you kept your mono so would not have to study so much:P
Sorry mate seen my opening and had to run with it.;D
Troy

[saurian]

Just a simple sponson digging in , bit of herbs and over you go.
But yeah one of my mates still can't handle my cat when the chop gets big.
Should see him white knuckles hanging on, " scared mate " i say , he just replies
"I'm waiting for the bang , but it never happens ".
Copie your fears will become other peoples over time.
Ta

[OPTI]

Well For What Its Worth I Had A Cat And Have Gone Back To A Mono,i Prefer To Have My Shower Hot With Fresh Water When I Get Home,not While Im Driving My Boat.
It Sounds Like The Old Cat Problem Which They All Suffer From To Some Degree,you Need To Run The Bow As Light As You Can,even Anchor And Chain Can Make A Difference.run Full Up Trim,if Your Running 4 Blade Props Go Back To 3 Blade.you Might Of Noticed The New Model 19 Kc Has Strakes Up The Front Of The Sponsons,this Is To Help Rectify This Problem,you Could Quite Easily Add Some To Your Hull It Would Help Enormously,or Do What I Did,sell It And Get A Mono.
Regards Opti;d

[mirage]

Just curious Opti, going from a cat to a mono, which mono did you choose?

[OPTI]

######### Formula 233;d

[OPTI]

Thats E-d-e-n-c-r-a-f-t F-o-r-m-u-l-a 233;d

[Fish Guts]

Well hi to you all. I have a friend/associate with a near new 6 mt kevlar cat, twin 140 hp suzuki 4 strokes. He has previously owned mono hull boats. Travelling out to his fishing destinations he appears to be happy with the new boat, BUT when it's time to come home so running with a following sea he say's the handling is frightening to say the least. In fact a coment was white knucklesfrom all on board. It appears the new cat can comfortably run out or head on at reasonable speeds and handles it well. When running with the sea he backs right off to approx. 12knts.His complaint is the boat appears to dive nose down with a lean to his side (driver side) down the face of a swell or wave with the apparent feeling that it wont come back up. The boat was returned to the manufacturer for inspection and they checked inspected and even ex-rayed the right side hull in case it was filling with water. they apparently found nothing wrong and returned the boat to the owner. The boat still reacts in the same maner. I personally have never owned a cat but thought some of you cat owners and in particular kevlar cat owners could offer some assistance. Oh it's apparent handling vice is so that he wont take his family out in the boat in any weather as it frightens them all.
I THANK ALL IN ADVANCE FOR ANY ADVICE MARK.:o


Hi Mark,

First of all i love that image on your sounder ,. some solid formations !!

We have a 35ft noosa cat with suzi outboards and have found that, generally speaking the faster the cat goes the better ride you will get. the more speed equals more air pressure under the hulls, resulting in massive lift and minimal porposing and digging in like you mentioned.

As a heap of the guys have previously stated just ensure the engines arent trimmed down too much. in our situation we dont need to work the engines ever, honestly the last thing u want to be doing is powering in and out of swells, it makes for an unpleasant ride for everyone and a bit of a shock at the bowser!!, and i dont think its warranted. in my opinion the only time youd really need to work the throttles is doing a lumpy bar crossing or going into some decent sized swell. id suggest a good 20 knots crusing speed , and dont touch the throttles until your coming in the leads. a following sea @ 12 knots cruise you will find doesnt give enough air pressure under the hulls for the cat to lift and glide over the swells, id imagine the boat would be literally surfing down the swells barely keeping up with the swell and wouldnt think the boat would have enough power at that speed to climb up the back of the swell, let alone generate enough lift for the hull to truly work.

As a rule of thumb tell your mate to trim the outboards up until you hear them cavitate, then lower until they bite in but dont cavitate. he will notice great lift, and the hull shouldnt be digging in at all. it shouldnt continue to dig in, well not majorly anyway.

bear with it and i can guarantee you wont find a better hull or mono for that fact, in that size to match the performance of the vessel in question. your mate should be able to sit back with his feet on the wheel preparing to crack a coldie when your safe and sound!

enjoy, and i can gurantee once he gets the hang of it, he;l never go back to a mono hull.

well done to your mate on choosing a great boat too, cant go past them. and great to see that kevlacat ensured everything was A1 on their end with the hull scan ect, if only some other cat builders (wink wink) would do the same with their clients after the sale !

hope this helps,

fish guts

[Grand_Marlin]

I remember my first ride in a cat after years of mono hull, I literally CR*P my self when we came of a swell at decent speed and the right hull dug in, the nutter behind the wheel is a member of this forum and have vast cat handling just powered her through it and she came up.


;D ;D ;D I stand accused ;D ;D ;D

[Kerry]

A little less criptic please Kerry, you seem to no the cats very well if your going to give advice how about tryng to make it a little more constructive..........................

ft, It might sound a little cryptic and not very constructive but that's simply based on the info provided. Without knowing the "complete' situation it is rather speculative to suggest anything, yet everybody else makes out as if they have all the answers? that's BS.

What I've read so far is that this is a fairly "new" 6m kevlacat with 140 suzzies, so I would have to assume this is in fact a 6.5KC and not a 6m KC especially if it has 140 suzzies on the back, lets assume (hope) so?

Basically a 6m KC runs downhill very well, even with 30 knots of sea breeze in shallow water behind it no drama's and if this one (assume) 6.5 with 140 suzzies doesn't then i'm a bit lost to expalin why, without further info.

Are these 6.5's with 140 4S's that far out of balance? I don't know! And I'm not prepared to make a comment without additional info.

Some of the comments about "working the throttles" simply make my head shake!

Regards, Kerry.

[copie]

Where'sthe boat based? He should get a salesman or someone from kevlacat to take him out when the weather is pretty bad put the boat through it's paces with a experienced driver so he has confidence that it wont do anything strange when he's driving

Ian
Thanks Ian and eveyone for all the advice please keep it comong. Ian the boat is based brisbane southside now get this "the selling dealer has apparently offered to go out with the owner but when requested to makes excuses apparently the last one was it might be a little to rough.
Thanks again to all keep it coming MARK.:-/

[copie]

ft, It might sound a little cryptic and not very constructive but that's simply based on the info provided. Without knowing the "complete' situation it is rather speculative to suggest anything, yet everybody else makes out as if they have all the answers? that's BS.

What I've read so far is that this is a fairly "new" 6m kevlacat with 140 suzzies, so I would have to assume this is in fact a 6.5KC and not a 6m KC especially if it has 140 suzzies on the back, lets assume (hope) so?

Basically a 6m KC runs downhill very well, even with 30 knots of sea breeze in shallow water behind it no drama's and if this one (assume) 6.5 with 140 suzzies doesn't then i'm a bit lost to expalin why, without further info.

Are these 6.5's with 140 4S's that far out of balance? I don't know! And I'm not prepared to make a comment without additional info.

Some of the comments about "working the throttles" simply make my head shake!

Regards, Kerry.



Kerry i do believe you are correct 6.5mt sorry for not being more specific. Just to add to a couple of the other replies he is not attempting to come back at 12knts but in fact slow to that speed so as to feel safe. Just one more thing this guy is not new to boating and regular trips to the shelf in prior boats "mono's" have been comon.
MARK

[Kerry]

The day Kevlacat started introducing dealerships was one of those bad days!

[couldbe]

Hi all,

After reading this thread I think that I am going to be in the same situation as
I have just bought myself a 5.2m Kevlacat with 70yammies. I am picking her up today and heading back to Mackay. I have never had a cat before either and am very interested in learning more about how to drive them. Does anyone know where that post on how to drive them from Grand_marlin is hiding?? I would be keen to take someone who knows how to handle a cat for a fish one day off Mackay in return for a few tips. Anyone keen??? ;D

Cheers
Daniel

[Tiddy]

i have owned 5.2 kevlacat for just over 3 years now & would only trade it for a bigger one.They do like to be run hard,20 knts is when the hull lifts & traps enough air to give that floating feeling.Runs alot better in choppy seas than a glass out(how often do we get a glass out)regulary run boat at 4500- 5000rpm for 45-50km\h Dont tend to work thottle much just set speed & head for horizon.when in a following sea, run as hard as possible cats love it.but cutting across a following sea is when she digs in.Trim down on the side that digs in to lift the nose on that side, leveling the boat,it will always dig in somewhat but can minimize this with trim.Have a pair of hondas on back(very heavy)& still run at about 3/4 trim for best ride. Just try trimming one side of boat then the other to get a feel for whats happening,practice makes perfect.Once u get used to it theres no going back

[OPTI]

YOU HAVE TO WONDER WHY A MANUFACTURER SILICONS THE CLEARS TO THE WINDSCREEN AT THE FACTORY?KINDS OF TELLS YOU THERES A PROBLEM.:o

[reef_king]

interesting that in a following sea you trim the kc out/up to reduce rolling/diggin in, when i trim my 7m coastal cat down, but i've still never burried a hull.

[OPTI]

You Might Of Noticed The Big Strakes N The Front Of The Coastal Cat,thats What Keeps The Bow Up,kc 2400 Dont Have Any,get The Centre Of Gravity To Far Foward And You Get The Death Roll,which It Sounds Like Is The Problem Here.its Also Dissapointing That Sm That Are The Dealer Are Giving Him The Stuff Around I Know For A Fact They Make 20 Grand On That New Boat Package>:(

[bastard]

A couple of weeks ago i was going from raby bay to horse shoe bay and a riviera cruise went buy heading to fraser,there were about 30 big rivs so from spit beacon to horse shoe bay was just slop but not real big probably only about a meter and i was sitting along side a power cat we were both doing 26 knots cutting accross a following sea and i was watching that cat bury its nose also i watched this for about 5 mins and couldnt beleive how badly this boat handled,i have never driven a cat so dont know if this was driver error or not but that was the same boat we were going to buy and after we saw that im glad we didnt.

[Noelm]

this will never end, the Cat lovers will have a come back for every negative, the mono lovers will also have a comback as well, I consider myself to be very lucky, I have owned and operated monos and cats for more years than I care to remember and my feeling is, that for every negative in a cat there are two positives, so I guess you can see what I have now, and unless you are doing something really 'soft" following sea is one of a cats best features.

[Antony]

Hi Mark

I had the same problem as your friend , before Christmas I upgrade from a 6m Seastorm to a second hand KC 2400 with 115 Yamaha ( petrol drinkers) ,on one of my maiden trips I scared my wife so bad she would no longer go out with me in open waters or in sheltered waters when the breeze was up , What happened , We were traveling 20kn plus heading in into Boyne island with NNE 15 to 20 nt sea when the boat dropped down one side of a wave so hard to the port the starboard motor lost grip and cavitate and then just as quick the wave picked us up and we fell in to the hole on the other side by that time I pulled back on the throttles and stopped to make shore every one was still on board it happen so quick that there was no time to respond I can remember thinking “ shit they go along way over with out rolling” , from that time on I was very cautious in any following sea , mind you my son was with on that day and continued going fishing with a gate amount of fear in any following sea .

When we got home from our fishing holiday , I was not impressed so I posted my concern on this form and got much the same response as you which did help me to not think so badly of the cat, but it didn’t help the wife she did not like it .

So what I did was I put the boat in at Horizon shores for a couple of weeks and headed for the pin every chance I got to gained some confidence and experience no fishing just playing , this did help I think because a couple of weeks later I was in worse conditions than Tannum (NNE 20 kn plus off 1770) , I was pushing along at 22 kn and the boat was cruising when the bloody thing did the same thing again this time I scared a whole new crew (and they weren’t a bad crew either) but didn’t scare me as much .
What concerned me was the motors losing grip, I think this helped to make the boat feel like it was going over feather than it would of if the motor was still in the water, so when I put a couple of new 140 Suzuki’s on we put them in the water a little more than the Yamahas and so far I have not had any concerns going across the pin bar, although I haven’t been out in anything much more than 15 kn to know how the boat will handle in heavy seas.

Anyway the son will still come fishing off the pin and he is happy if I let him drive and the wife is back on board and has come out over the pin ( she must now trust me?) the 1770 crew are asking to go again so things are improving.

The more I dive it the more I like to drive it .

I think once your friend has mastered the boat he will gain confidents of the crew and than there will be no more white knuckles.

Anthony

[Owen]

Just out of curiosity...

If KC went to the trouble of x-raying the hull ( I think some sort of ultrasound is more likely), what did they say?
IF the problem is truly how it is driven, did they not offer to demonstrate that by water testing it with you on board?

Just seems curious.

[Kerry]

....What happened , We were traveling 20kn plus heading in into Boyne island with NNE 15 to 20 nt sea when the boat dropped down one side of a wave so hard to the port the starboard motor lost grip and cavitate and then just as quick the wave picked us up and we fell in to the hole on the other side by that time I pulled back on the throttles and stopped to make shore every one was still on board it happen so quick that there was no time to respond I can remember thinking “ shit they go along way over with out rolling” , from that time on I was very cautious in any following sea

Yes

non counter motors, unless trimed properly a hull that will want to roll to port, a sea that wants to lift the stb stern and there's generally a hole under the port bow :)

yeehaaa

Rather different to a true following sea but it's all in the trim (port down sometimes way down this is the main driving engine, stb up but not enough to break) and be very mindfull that little boats fall into big holes.

Then again nobody has yet convinved me a 2400 with 140's is balanced anyway :)

Regards, Kerry.

[finding_time]

Yes

non counter motors, unless trimed properly a hull that will want to roll to port, a sea that wants to lift the stb stern and there's generally a hole under the port bow :)

yeehaaa

Rather different to a true following sea but it's all in the trim (port down sometimes way down this is the main driving engine, stb up but not enough to break) and be very mindfull that little boats fall into big holes.


Regards, Kerry.


Thanks for that Kerry!! Made alot of sense and was a usefull bit of info for me;)

Ian

[julian1]

take the time and learn to drive it. it will take 30-50hrs to become familiar with your cat and learn its handling traits. in a true following sea behind you you will never dig both hulls in at once, but side on or on the rear quarter if you feel one side start to dig in then just turn into it and it will pick it up instantly. It can feel unnerving but you will get used to it and the speed you can maintain will shock you. I recently returned from the shelf in a 20kt plus side wind and passed so many mono's of larger size that were broaching etc. we had a couple of instances where it would start to dig in but just steered out of it. also since i have fitted Suzuki 4 strokes it actually handles better which did surprise me. I t has much more lift and power but with heavier motors (this is in a 660 Noosacat) drive to the conditions but get used to it first, i will use steering rather than adjusting throttles indiviually to pick up a dipping hull

[wadeo]

Like you im a relatively new owner of a cat since fully restoring a 7.7m 89mod shark cat. I have had it on the water now since last november. Having mono hulls all my boating years. whilst restoring the gutted old cat i'd brought ,all i could think of was this legendary ride you here about from so many different angles of the boating world. I remember my first few rides once this cat had hit the water in moderate conditions i felt a little disappointed that it basicly wasn't the jump behind the wheel, drive easy ride i'd expected specially trying to drive it like a monohull. Some really eary feelings as it drove down a wave like a bus driving down an imbankment not surfing it like i was use to. After a while i stopped fighting the hulls and just let them do as they wished. once i tried this our ride got better i found i could travel quicker more comfortably trimming the bow up and traveling nothing under about 15 to 18 knots so air built up in the tunnel cushioning the landings in most cases that wave that used to rattle us isnt even felt now. Letting the cat tack from one hull to the other is perfectly natural and i agree those one sponsen dig ins on the bottom of a wave in a following sea still occasionally scares the shit out of me.I Have only 110hrs up behind the wheel of a cat and now i feel totally safe and can travel at upwards of 25kn through most conditions. I alter my coarse to get maximum comfort ride and that is usually cutting diagonally across the sea keeping in mind i need to keep enough speed to create lift in the tunnel to acheive a soft ride. You will get use to knowing when your cat is going to dig in and you'll naturaly know how to react to it give it time. I reckon now i have found my legendary ride i'd heard all about and rekon to anyone once you go a cat you'll never go back!

[freddofrog]

...unless trimed properly a hull that will want to roll to port, a sea that wants to lift the stb stern and there's generally a hole under the port bow ...Rather different to a true following sea but it's all in the trim (port down sometimes way down this is the main driving engine, stb up but not enough to break) ...

Sorry but this doesn't make sence to me, please explain?...if you trim the port enging down/in, that will bring the port pontoon down. Wouldn't you want to do the opposite to level out the boat as it will be the port side that will be dropping down the wave, assuming your are tracking across a following sea which is coming onto your starboard side.

[Noelm]

most cats (especially with pods) will react diagonally to trim, (if you get what I mean) the starboard motor trimmed out/up will lift the port bow, kinda funny huh! I think it has something to do with the boat being sort of square and the motors on each 'corner" it is also one of the reasons newcomers get all crossed up in driving one.

[finding_time]

Sorry but this doesn't make sence to me, please explain?...if you trim the port enging down/in, that will bring the port pontoon down. Wouldn't you want to do the opposite to level out the boat as it will be the port side that will be dropping down the wave, assuming your are tracking across a following sea which is coming onto your starboard side.

As noelm said trimming port down definately lifts that side, only once i started playing with the trim did it truely make sense:)

Ian

[Kerry]

Sorry but this doesn't make sence to me, please explain?...if you trim the port enging down/in, that will bring the port pontoon down. Wouldn't you want to do the opposite to level out the boat as it will be the port side that will be dropping down the wave, assuming your are tracking across a following sea which is coming onto your starboard side.

Trimming down/in the port engine lifts the port hull. Trimming up/out the stb engine drops/lowers the stb hull. With a balanced boat, non counter props and equal trim a cat will favour lying over on the port hull and can be levelled with either engine depending on the conditions, it's just that it's normally the port engine that goes down (lifts the port hull) as the stb engine has less trim to move . Depending on the conditions one can do all sorts of things with twins like this.

Even when drifting through the tilt/trim of each engine and steering you can make a cat drift anyway you want.

[Noelm]

just to add, once you have got the hang of the diagonal trim thing, if you have the swell/sea/chop whatever on a stern quarter, if trimmed right, you can as fast as you like (within reason) and have NO worry of any of this "digging in/broaching" nonesense that non cat owners seem to see as being such a big issue, trim in ALL boats, mono or cat is important to get the best out of them, but they are different and thats all there is to it, one of the worst of all cats with a quarter sea and not trimmed right is what most people believe is the best of all cats, the old 23 footer, I have spent thousands of hours in one of those carrying loads that would make a 23 foot mono crap its pants, and in capapble hands, they are real goers, but in a learners hands they can be a whole different "kettle of fish"

[Diablo]

Hi guys,just got a 18ft shark cat only been out a couple of times,Im glad you guys sorted out the trim situation in the last couple of posts as i was getting a bit confused,when I took th boat out for a test run the previous owner showed me a few things you should and shouldn't do,the main one pulling up too quick she wants to bury the nose and from what ive been reading this is a common problem with 18ft sharkcats,I was wandering would a little more bouancy up front(say in the first third) in the hull fix this problem or would it just throw the balance of the boat out,look forward to hearing from some experts,Thanks.

[Kerry]

Nah just be aware the 18 is light in the bow. They had many goes at getting the 18 right, then they gave up!

[Grand_Marlin]

Diablo,
Are you talking uoyancy as in say foam filling the hull?
If so, wont make a scrap of difference.

If you are talking re-designing the hull, then you are biting off more than you can chew.

The downfall with the majority of 18' cats is the windscreen / cabin is too far forward and therefore the weight of the driver / passenger/s causes it to be nose heavy.

The best thing you can do is get your weight distribution of everything on board correct.

Cheers

Pete

[freddofrog]

man cats are complex little beasties, thanks for the explaination

[Diablo]

Yeah pete I was just wondering whether foam would have any effect,re-designing a bit beyond me,thanks to you also Kerry, will put some photos on soon as so you guys can help me identify what year she is as this intrested me in previous discussions Ive read.

[Noelm]

a lot here might disagree on this, but aside from the lack of lift in the bow ANY (almost) 18 foot Sharkcat, would be the most forgiving boat bar none, Mono or Cat, unless you are a complete ninnny you can run then with pretty badly adjusted trim and they still go good, in the breakers, in big chop, side on anyway they will go (given good power that is)

[Grand_Marlin]

I would love to have a play with an 18 footer and add wave piercers to the front of the hull....

I think this may go a long way towards fixing the droopy bow problem without affecting the ride.

Cheers

Pete

[Deiter]

Hmmmm, interesting concept Pete.

Just how do you think one might go about such an exercise?

Also, are their noticable advantages having a wavepiercer, aka the marlin broadbills? Antone ridden one with and without?

Damo

[blaze]

I would love to have a play with an 18 footer and add wave piercers to the front of the hull....

I think this may go a long way towards fixing the droopy bow problem without affecting the ride.

Cheers

Pete

Hi Pete
Local boat builder has built a 6m concept cat, displacement boat, orignally powered by twin 25hp motors achieving a WOT of 18knots still in displacement. Back to what you said. He at one time fitted wave piecers to get bow lift and cut them off again put lifting chines for a far better result.
Currently the builder for cape cats
cheers
blaze

[Deiter]

Yeah Blaze, I remember you mentioning something about that boat in another thread that died b4 you could elaborate.

I'm eager to know more, e.g. size(is it trailerable?), sponson configuration, build material etc. I also remember you saying that this boat was about to be upgraded to bigger motors. Any news on that front?

If all this is true (and it sounds too good to be), then surely it warrants further investigation. Please, Mr Blaze, sir, any more info would be greatly recieved.

Damo

[blaze]

Hi Damo
If member seabug sees this he has some recent pics of it, he was showing some interest in purchasing when it come on the market (think he is haveing second thoughts). I havnt seen the boat for sometime but he is upgrading to 60hp etecs and I think he is trying for about 24knts cruise at about 1/2 throttle with the boat still running in displacement. It was been built of a close cell foam sheeting and glassed over (name of product is slipping my mind ATM). I would buy it tomorrow if I had thge money. If you would like his PH number I can get it for you and you could talk direct to him. Nice fellow and would discuss it with you just because of his belief in the product and his love of design and boats.
cheers
blaze
Ps
Couple of things I really like are that there are no scrubbers, no need as there is only a stainless rail at the back of the boat, hard top, left hand helm and the thing goes for bloody miles on minimum of fuel

[Deiter]

Yep, cool, pm me the info. Also, what the blimmen 'eck do you mean by 'scrubbers'?????
To me, scrubbers were the dirty girls at school who used to invite you behind the bike shed at lunch. Oh, to have that time again............woops, ah...yes, sorry, you were saying?

[lee8sec]

Slight side track, how do the single stern drive models handle in rear 1/4 on sea's? With only 1 motor to trim do they suffer the nose dive worse than twin o/b's? Thanks Leigh

[gavsgonefishing]

Diablo,
Are you talking uoyancy as in say foam filling the hull?
If so, wont make a scrap of difference.

If you are talking re-designing the hull, then you are biting off more than you can chew.

The downfall with the majority of 18' cats is the windscreen / cabin is too far forward and therefore the weight of the driver / passenger/s causes it to be nose heavy.

The best thing you can do is get your weight distribution of everything on board correct.

Cheers

Pete

Interesting concept Pete, I am currently redesigning a cat hull because it is a pig. The thing had a bow in the middle of both sponsons (as much as 50mm), and it is a early assymetrical hull (no beers for guessing the make) with a "tail"which was used for the single motor setup. Overall result, a very bad ride, dancing all over the place with no real ajustment on the trim. This left the boat slow, never really getting off the plane eventhough there is a heap of HP. All the strakes are wrong or in the wrong position.

As part of the exercise I will be extending the hull down by a heap, symetrical design, fuel tanks will be lower (and bigger) as well and I will be reshaping the entry point of the sponsons so there is more boat in the water, and the boat will be cutting the wave earlier. There are a HEAP of other mods as well when the boat gets flipped right way up

Iwill endeavor to get some pics up

[insideout]

blaze , could you pm me the info as well thanks! I am finding this thread very interesting, especially for new owners of cats like myself, and would like to find out as much info as possible.

[Kerry]

The wave piercer concept and current fleet of Incats actually developed from an 8m concept way back in the 1980's. However this wave piercer concept is really not adaptable or modifiable to the typical 5-6-7-8m cat as most are accustomed too.

Some alloy makers have tried an extended (bulbous) bow type concept but it's really not close to the typical wave piercer and questionable if in fact it actually worked?

Regards, Kerry.

[insideout]

while i was at the santuary cove boat show, i saw a cat that was built in wa,and the guys on board clamed that this breed of cat actually banked in like a monohull in a turn..Iknow that mine does the opposite, and was a bit suprised to see the video footage of this cat loaded evenly with crew actually leaned into a turn!!Not only that, it turned at speed to within 3 lenghts of itself!! Two things mine does not. Especially the turn at speed!! It does not like it much. It is interesting that cat hulls can be so different to give such different preformances. I tried to geta look at the hull config, but could not.This footage has sparked my interest in designs that can help a cats ride.

[hungry6]

Insideout, I wonder if the manufacturer you mention had a quick flick and add some herbs to the outside motor, which would do the same, dunno about the 3 lenghts bits. LOL. Don't quote me i'm still learning to drive mine.
The law of physic is pretty hard to overcome once you are set within a parametre.

[lenm5]

Cats leaning out on a turn...:-/
What do you think a car does when you go around a corner fast.
Unless you want to tow tubes who cares how a cat turns - the only turn I do is to come home from the shelf;D

[copie]

Well i have to thank all of you guy's, i started this thread to gain some help for a friend. WOW i never expected to get so much help. It certainly appears that new owners and drivers of cats all brands and sizes just need the hours behind the wheel in all types of sea conditions and a little encouragement from other owners that the cat pleasures will soon come.
Thanks to you all again MARK.

[Blackened]

G'day

The dominators will lean in on a turn, due to having a hull similar to having a tunnel carvel out of a mono.

Regards to a cat turning within 3 lengts of itself ?? On the 7M coastal Cat we had it at full noise and the put her into a full lock turn. Scary at first but totally safe, handled like on rails.

Dave

[insideout]

I should clarify, " at speed" what i mean is about 15 knts, not full tilt wot. Lemn5 obvoiusly you dont have much to dodge on the trip out - home, Whales, shagging turtles, longstrings of crabpots,ect.

[Big G]

http://www.ausfish.com.au/vforum/images/attach/jpg.gif


I've been watching this thread with interest and I'm glad I own a 6m alloy jaycat.
great boat with good speed and economy, easy to drive in a following sea, drives great in most conditions, just like a limo, quiet and smooth.

Only a fool would try to hard turn a fast cat above 25knots. Good turns are usually safe and smooth with a common sense driver. Not all cats are the same and most cats are influenced by driver experience and load. Most cats and mono hulls for that matter don't drive as good in a heavy following sea.

I think that kevlacat owners should not be discouraged by some comments posted as I have been in more scary rides in mono hulls than cats. I previously owned a twin turbo engined 28ft shaft drive bertram.... the best reputation as a sea boat.... was not real happy in a big following sea but was still one of the best and safest mono's made.

My cat is great...6mt. twin 140 4s' plate alloy by Offshore Marine Master.

[Dean1]

Very nice cat indeed Big G!! Just wondering how you would compare an aluminium cat to a fibreglass cat for ride quality?? Is the fibreglass a bit quieter as in doesnt shudder and thump( even tho cats rarely thump) as much when they touchdown or is the ally up there with the glass? Ive been in lots of different glass cats( sharkcats, kevlacats, coastalcats etc.) but never an aluminium cat.. Always been very curious, once again thumbs up for your rig it looks great! :P

[Big G]

Dean,
I guess when we think alluminium we think tinny and your right that would be noisy...... but 4mm alloy plate at the top of the tunnel then 50mm of closed cell foam sandwiched between another 4mm plate floor, covered by good quality marine carpet makes for a sound proof barrier between you and those big waves.
The full range of boats made by OMM all have positive flotation using closed cell foam blocks...... it has also been used under the floor of the queen size bed which covers the entire front section where most tunnel thumping might take place.

This cat is very quiet and with the sealed cabin door and 2/140hp 4 strokes giving around 20knots at 3900rpm you can imagine how comfortable and quiet cruising is......like I said it reminds me of driving a limo.


http://www.ausfish.com.au/vforum/images/attach/jpg.gif

[Big G]

Dean,
if you look at the photo of my boat under construction you can see the frames above the tunnel top... that is where the closed cell foam planking goes..... then the floor... then the carpet.
also the queensize bed up the front has carpet then appolstery matress.
OMM also use this foam in all their inbuilt ice boxes.... the best insulation you will ever see.

[Dean1]

Dean,
if you look at the photo of my boat under construction you can see the frames above the tunnel top... that is where the closed cell foam planking goes..... then the floor... then the carpet.
also the queensize bed up the front has carpet then appolstery matress.
OMM also use this foam in all their inbuilt ice boxes.... the best insulation you will ever see. Looks good Big G.. Youv definetly got yourself a solid investment there. Id love to go for a run in one of em.. OMM build nice boats mate and your boat is a fine example ;D

[Big G]

Looks good Big G.. Youv definetly got yourself a solid investment there. Id love to go for a run in one of em.. OMM build nice boats mate and your boat is a fine example ;D


What area are you from?

[lutjanus]

Lots of good advice in here.I have owned 3 Kevlacats,as well as 3 other brands over the years and done 10000hrs in em.Word of warning though -dont drive them to hard down sea as some are advising.Back off if worried.I buried a KC once through this.NOT GOOD FEELING>

[jeffo]

interesting thread!! having fished on a few different KC's of a few different sizes i can tell you all of them do the little "cat walk" in a following sea....but who would have it any other way. Once ya get used to it i reckon its great fun- they seam to double in speed down the face!! A mate fished the cairns heavy tackle season last year in his 6.5KC and encountered some horrific conditions (30 knots plus) and the boat handled like a trooper. Have confidence they wont fall over and like others have said put the throttle down that little bit more to get them rightout of the water.

[Marlin_Mike]

mate theres a 6.2mt Kevlacat at John Crawford Marine.............. wouldnt i love to drive out with her.................only a paltry $ 68,500.00.............. twin 115 4 banger yammies on the back

Mike

[Deiter]

sounds like a good price Mike - go for it!!!!!

[saurian]

Mike ditch the reef prince , just buy it . Think how much longer you will live not
stressing about not having a cat.
Ta
Hey deiter i checked my bum , no grubs but !!!!! lol.....

[Deiter]

Mike ditch the reef prince , just buy it . Think how much longer you will live not
stressing about not having a cat.
Ta
Hey deiter i checked my bum , no grubs but !!!!! lol.....

HA ha, actually, the correct answer is ....FESTERING!;D ;D