Any advice on handling a kevlacat 2400

[Antony]

I recently brought a 1998 2400 with 2001 115 Yamaha's , over Christmas and new year I went off shore from Gladstone with 3 other mono hull boats all about the same sizes , on the return trip bake to shore I was very disappointed to find my self wallowing in there wake and then being left behind . we had a 15 to 20 sse blow and i was heading in a westerly direction #the tide was against the wind which made the waves stand up quit a bit #, my boat felt very awkward to handle and at times through the crew about very dangerously !

Can any one tell me if this is the down side of a cat or do I need to know how to handle the cat in these conditioners ?

Thanks for any help or advise
Antony

[Blackened]

G'day
The worst angle for a cat to ride is on a head on sea, they may begin to slam in the tunnel a bit... albeit, will maintain a better speed than a mono in the same conditions.

Driving a cat you will need to learn how to, it's completely diferent to driving a mono, so you will have to learn new tricks.

There are plenty of powercat owners in your general size here.... Grand_Marlin, 23sharkcat, reefking just to name a few, I'd suggest taking someone experienced with cats out with you for a 1/2 day just to get used to driving the boat and the conditions. Remember a cat will run better at speed, this is because of the pocket of air that sits in the tunnel as they ride up on the air pressure.

Dave

[Kerry]

No not a downside of a Cat and the direction/sea conditions are not the worst type for a cat. I wouldn't expect someone with a new boat and especially a Cat to be fully conversed with how to get the best out of it regardless of previous boating experience.

This is something that will come in due course as you get the feel for the boat in different conditions.

Take it one step at a time, don't rush into expecting too much at this point until you get some hours up behind the wheel.

[hungry6]

Take someone who has good knowledge on cat performance and the difference is like day and night, I was sceptical with cat performance at first, but a member on this forum show me what a cat can do and I'm lost for word on their performance. My first cat encounter was nervous and feels downright dangerous, things don't seem to behave the way they should as in a mono hull, but you're not in a mono hull.

[saurian]

Antony,
Hi I'm in Mackay so I think the conditions are similar to gladstone, sounds like you may have dug in a sponson or 2.
Not a nice feeling even in small chop.
Driving beam on , which is what you sort of desribe is not the way
to acheive a flat level ride , depending on conditions it can be a very
uncomfortable way to travel.
Tacking slightly one way then the other to suit the conditions is sometimes needed to avoid the negative sides of the sea state.
It may seem like more distance but once you get the hang of it you will blow those monos away in comfort.
Imagine your 2400 as 2 boats travelling side by side , one hull goes up the crest as the other is still down in the trough. (And visa/versa)
Thus the awkward feeling (especially if it's a hardtop) of going up then down each crest as each hull hits the crests seperately.
If you surf down sucking chop on say the starboard sponson it will be dropping down the wave before the port side and that errie feeling continues until it bottoms out and starts to rise again.
The bottoming out can either be gentle or a severe gripping boat spinning affair.
You have to learn what your hull can do in regards to this side on angled
attack, if you go to far it will dig in so you gradually with trial and error
learn what is alright and also learn what will make everyone on board get white knuckles and brown undies.
I call it waddling, sort of squishing from side to side as each sponson makes it's rise and fall. It doesn't happen straight away , some peolpe get it sooner than others , but it is by no means a fault , it is a characteristic of twin hulled boats. And they are called cats.
I took a mate out recently and he shat himself coming home in 2.5 m of what you described, I was able to maintain 18/20 knots and every now and them I had to turn and hit a breaking chop wave nearly head on ,
My friend was very unnerved to say the least but we still maintained a steady cruise and arrived back to the ramp 30 minutes quicker than 3 other mono's, I was not unnerved by all this waddling , as I have learn't
what my 2 hulls in the conditions can do.
I think you should go out in better weather and push her down smaller chop and see what happens and practice how your boat excells over others of a similar size, speed, trim, and angle to sea state will all dictate
whether it's a good or bad ride.
The one tip I learn't that helped me the most is that a cat is longer
on the diagonal , that means more water line length on a diagonal.
So a 6.5 m cat is more like a 7.5m mono.(example only , please)
Use this to your advantage.
Hope that may help a bit.
Ta.

[Kerry]

Out of interest what were the other 3 vessels you were comparing your Cats performance too?

[troy]

Kerry,
It was two cruise crafts. ;D ;D ;D
Troy

[saurian]

It was bruisecrafts more like it troy.....
Kerry , 560 quinnie cuddy , wahoo 5.8 ish ( longboat), haines 6.8 ish
rebuilt , looked nice full hardtop .
I was doing 18/20 knots, trimmed down.
But kerry please don't out of interest make an issue out of this .
I may have gone quicker because of cats ability in conditions,
or maybe they where all having beers and trolling , don't know.
I think because of cat ......
Ta.

[Shanoss]

A haines 6.8ish??? my god man! you must have a few too many beers whilst trolling me thinks ;)

[skippa]

Kerry,
It was two cruise crafts. ;D ;D ;D
Troy


ROFLMAO # ;D ;D ;D ;D ;D ;D ;D ;D ;D

The next thing we'll hear is that NQ 2 foot chop playing up again ... # ::) ;D

[skippa]

opps double post ... better lay off those Jimmys again ;D

[Kerry]

Out of interest what were the other 3 vessels you were comparing your Cats performance too?

Wasn't interested in your comments saurian, the question was in regard the actual original post, too Antony!

So saurain don't get up on your tippy toe, absolutely nothing to do with you!

[saurian]

Man your questions are a little to bi , for my liking.
No offence meant but kerry you do bait up the questions at times.
Ta.

[Kerry]

Saurian, Antony mentioned 3 other boats, the question was, what were these 3 other boats, it's that simple, you were not mentioned so what's all the bait BS? If the question was directed to you it would have commenced such Saurian, ...... ok, it's that simple

[saurian]

Yeh , simple misunderstanding, no prefix of any names so yeh thats what it is.
No worries Kerry.
Ta.

[Stuart]

The 2400 is a nice riding hull, ho doubt about that. I have spent years on the Kevlacats, either decking or behind the wheel. I must say that my two favorites are the 5.2meter and the 9meter, man if I had the coin I would own both of these hulls. Kevlacats don't have the bad habits of say the old shark cats where broaching was a scary hell rid most times coming home with a following sea. Spent many years working on a pro shark cat and I can tell ya all its the last time I will ever go on one. I lost count of the amount of times we almost rolled it coming home. I have also been in the Kevlactas where the water was about to start rolling over the gunnel's. If you trim the boats right and drive them to the conditions you wont have a worrie in the world. Your 2400 will be fine mate, just remember when heading out with a sea coming in on your left side always trim the left motor up a bit more than the right. and the same goes for the right. This stops most of your rock and roll when under way, keeps the boat pretty level. And most importantly let the cat walk its self across the swell and chop, most people get into trouble when they try to man handle cat's. No one in their right mind can compare a cat to a mono hull because their are absolutely no similarity's between them. Anyone with any sense can see they look nothing alike and I can assure you all they act nothing like a mono hull. I laugh my gutz out watching people drive a cat for the first time, the look on their faces says it all.

Stu

[Kerry]

....just remember when heading out with a sea coming in on your left side always trim the left motor up a bit more than the right. and the same goes for the right.

Maybe you might like to clarify this one especially with regard counter and non-counter rotating motors?

This particular 2400 with 115's would probably have non-counter rotating motors?

[Stuart]

Kerry

Most if not all the cats I have been on didn't have counter rotating props. They all had hydraulic steering which made a hell of a difference and can transform a cat in 5 minutes of installing..

Stu

[Antony]

Thank you for all your comments and advice, It seems I need to learn to drive the cat like a cat and not a mono , I had been lead to believe in all my per purchase inquiry’s and test runs that the kavlacat would eat my cruise craft mats , In fact there was 4 other boats 3 – 625’s and 1- 550 on one trip home when a 15 k northerly was blowing and we were heading west I left 5 minutes before the 550 on a 50 klm trip back to port he past me about half way , I was not impressed , I could not go any faster because I am certain there would have been mutiny on board and I would have been forced to walk the plank , I did try changing the direction to the waves but to have a comfortable ride I would of had to of travel at lease another 10 klm , to do this at the time did not make sense now looking back I think I should of done the extra klm , next time I will try it.

I must say that the boat handled impressively in all other directions to the sea even directly into it .

Saurian , your comments have made me think again , thanks .

Troy , do you know me ?

Antony

[23-sharkcat]

Stuart was correct I would have had that look on my face The first time I tried crossing a bow wave off a 45 flybridge coming back into the Brisbane River. I made the cat point directly into it and it would have looked fantastic if some one had taken a photo as I would have to guess that I was about 10 feet from the water when I left the tip of the wave. Keep in mind I was doing about 35knts at the time.

When she landed it was quite smooth, Not what I was expecting, And the look on my face went from SH#ting myself to looking like buzz lightyear within 2 seconds. I had to do this for my farther and brother who only second before said "do you think we should be going this fast"...I think I still have there fingernail marks in the dash.

I think that because I have twin inboards in my cat it is not stern heavy as some of the ones with big outboards.

There has also been a couple of times that going side on into some 1-1.5m chop that I dont like the feeling of the sponson digging in.

But saying all of this there is nothing like going head on into some 1.0m chop and still maintaining 30-40knts. Try and do that in a Mono.

[JB]

Out of interest what were the other 3 vessels you were comparing your Cats performance too?

Wasn't interested in your comments saurian, the question was in regard the actual original post, too Antony!

So saurain don't get up on your tippy toe, absolutely nothing to do with you!


Ha, good ol kewwy at it again #::) #wat a weapon #lol

[Kerry]

Out of interest what were the other 3 vessels you were comparing your Cats performance too?

Wasn't interested in your comments saurian, the question was in regard the actual original post, too Antony!

So saurain don't get up on your tippy toe, absolutely nothing to do with you!


Ha, good ol kewwy at it again #::) #wat a weapon #lol

Nothing to do with you either you fool! Just JB mouthing off as usual and saying absolutely nothing, get a life you clown! Be constructive JB otherwise simply pull your head in.

[Kerry]

Stu, I’m a bit surprised a 9m KC would not have counter rotating props and especially once one gets up in HP? The 5.2 would certainly have standard rotating engines. The type of steering is really not an issue as to how a Cat performs.


….just remember when heading out with a sea coming in on your left side always trim the left motor up a bit more than the right. and the same goes for the right.

While I agree the trim is all important it is really not typical that the left engine is trimmed up a bit more than the right and this statement is too specific and not necessarily the case but this does depend on the engines, boat setup and the conditions.

That might be an indicative comment with counter rotating engines as all things being equal a level boat will be equal trim (no weather/sea etc) and any sea on the port side would probably result in higher trim on the left but this would not be the case with non counter rotating engines as the port engine under good conditions is already trimmed down compared to the starboard engine.

So with non counter with a port beam sea the left engine would be trimmed up but very rarely would exceed the trim of the starboard engine, sea dependent of course but in these typical 15/20 type conditions if the port engine is trimmed more than the starboard then it is one very badly balanced boat to begin with. A badly balanced boat is not something engine trim should be relied upon to fix

Regards, Kerry.

[Kerry]

Antony,

No comparable Cruisecraft will get away from a KC2400 in those types of conditions.

However a westerly heading with a northerly is close to the worst possible direction/sea combination but not quite. The worst would be a westerly heading with a north-easterly, starboard stern quartering sea.

This situation is compounded with non counter engines as you have a pair of engines that under load want to roll the hull to port, a sea that’s trying to lift the starboard hull from the stern and the port bow wanting to drop into the downhill troughs. This type of situation is something you need to be very aware of.

In these conditions it’s the port engine that will be working the hardest, be trimmed a long way down (tucked in) compared to the stb trim and have a bit more power on. The port trimmed down lifts the port side and trimming the stb up tries to keep the stb side down and stop it from lifting, countering the engine torgue and compounded affect of the sea. The overall trim and relative balance is something that will come with time and experimenting. Incorrect use of trim can put a cat in a dangerous situation but with a Cat the trim is best friend when used properly.

The port engine you might notice over time uses more fuel, which is fairly normal as it works the hardest. Also would pay to check your props and if standard 19’s (too big) they need to disappear sooner than latter. You must be able to achieve max WOT (plus) under full load with whatever props you are running with. Standard 17's are about right.

Regards, Kerry.

[Owen]

I normally dress to the left.
If I bought a cat would I have to take this into consideration? [smiley=happy.gif]
When you get the cat handling properly Antony, can you tune my VCR?

Actually I'm finding all this very interesting.
Always toyed with the idea of a cat if I upsize. Never realised they required that much finessing

cheers,
Owen

[Mr__Bean]

Each time I read these posts I can't help but wonder why you guys persist with Cats.

With the recent rollover in Moreton Bay, and the others that experience near miss occurences in their cats, it really makes me wonder if the extra knots are worth it in the end.

- Darren

[Kerry]

It probably wouldn't matter to some, they will continue go on believing what ever it is they want to believe for their own reasons, without really knowing why!

There's really not a lot of point in even attempting to explain things to some people, it would be a total waste of time and energy.

However there is one thing that has been consistent for about the past 35 plus years, whenever people have got in the sh!t one really hasn't got to be all that clever to notice what the majority of vessels are, that for some strange and obviously completely unknown reason (and this has a name 8-)) to some get to pull these people out of the sh!t.

Hindsight doesn't serve the doubters what so ever.

Regards, Kerry.

[soulfish]

mr bean what was the latest rollover in moreton bay ? ::)not another 7m dominator was it. ::)

[Stuart]

Kerry

I have driven cats that didn’t have counter rotating props nor did it have hydraulic steering. To say it was a pig to drive was an under stament. We fitted hydraulic steering to this cat and man did it make a difference, it was out of this world. It stabilized the engines “no play in linkages and so on”. It made the cat ride better, straighter, and felt more stable on the move than before the hydraulic steering was fitted. This cat didn’t have counter rotating props, it’s got twin 70 evinrudes and the props spin the same mate. As for trim on the way out, it’s been my experience and that of nearly the whole cat fraternity here on the Sunshine Coast to trim the engine on the sea ward side. This does prevent a great deal of rock and roll and I know this by thousands of hours experience on cats. If you have a sea coming in from your port side then the port sponson will want to lift with the sea, the port engine tends to exaggerate this by holding in this position for that bit longer. By trimming the port engine up the boat losses grip on that engine and so the boat will always want to drop faster on the port side. By trimming the port engine down it over exaggerates this by lifting the sponson and holding up longer. I have played around with all different engine trim positions and have found this to be the best. Not only myself but pro fisherman that spends every day on the water, along with 200 other cat owners here on the coast.

Stu

[23-sharkcat]

"The port engine you might notice over time uses more fuel, which is fairly normal as it works the hardest. Also would pay to check your props and if standard 19’s (too big) they need to disappear sooner than latter. You must be able to achieve max WOT (plus) under full load with whatever props you are running with. Standard 17's are about right."

What do you mean by 19's are to big?

I have 15 1/4d x 21p and I still reach WOT easy at about 4200rpm. Are you talking about outboards only?

[ozscott]

I dont know much about Cats. I know years ago - 70s - the most common rescue boats used by the Coast Guard were Seafarer Vagabonds and the 675(?) Haines Hunters (the big haines). I have one of those Vagabonds and Im happy with it. The Coast Guards etc eventually moved to the big cats. Am I right in saying that the main reason for doing that was the extra platform stability at rest for rescues? I dont know and would be interested in the feedback of guys that know first hand or are otherwise more knowledgable than me about rough water boats - which wouldnt be hard!

Cheers

[Kerry]

Coastguard/VMR's etc were moving to Cats in the early 70's for a number of reasons. One being the capability over and above a mono for the purpose. Community helicopter services were extremely rare as was many other organisations as they are today, including the water police in most locations.

Big Cats (as such) were really not part of the scene and these days with all the vessel requirements and other issues many organisations have generally gone for bigger conventional vessels to augment the mixture of rescue capabilities available.

[Kerry]

"The port engine you might notice over time uses more fuel, which is fairly normal as it works the hardest. Also would pay to check your props and if standard 19’s (too big) they need to disappear sooner than latter. You must be able to achieve max WOT (plus) under full load with whatever props you are running with. Standard 17's are about right."

What do you mean by 19's are to big?

I have 15 1/4d x 21p and I still reach WOT easy at about 4200rpm. Are you talking about outboards only?

Outboards only? With regard the subject of a 2400KC, no other choice.

Engine problems on many Cats can be attributed to the props, most are too big and generally setup for speed which is totally the wrong thing to do.

WOT for a pair of 115's on a 2400KC would want to see 5600rpm

[23-sharkcat]

Kerry are you saying that I should go smaller on the props? and why...

[soulfish]

oz scott .mate i'm no expert on cats either,i've owned 4 seafarers last 2 where 6.2 vagabonds and was very happy with them.for the last few years i've always wanted to own a cat to see for myself how good they are or not.finally after a fair bit of research i found and decided to buy a 2700 noosacat.after the first 5 -10hrs i thought that i'd made a big mistake felt very awkward to drive.65 hrs later mate words can't describe the ride totally blows me away how soft it is i can cruise 45-50 klm'shr in absolute 20-25knt shit and not land hard.only a few weeks back i checked the bom forecast 24knts at the cape lets go high speed trolling no problem obviously not soft hitting them head on ,just veer 10-20degrees and it never landed hardat all.i'm pretty exited about my cat because with every trip i grow with confidence in the hull and what it can do. i'm not saying it's the perfect boat that will never be invented.my seafarers served me well but i would find it hard going back .at the end of a big day offshore myself and my fishing buddy never feel no where near as drained as we used to in our monos. ;D

[23-sharkcat]

soul fish what have you got powering your 2700 and what sort of performance do you get from her.

Is the 2700 the same as a 700 series mark 2 sharkcat the hull looks identical.

[ozscott]

Sounds good Soulfish - I have wondered for some time when one day I move to a bigger rig. To be fair to the old Seafarer 6.2 is a hell of a lot smaller than a 27 foot cat (and a lot lighter!). Thanks for sharing your story mate because that sort of balanced report is well recevied.

Cheers

[soulfish]

23 sharkcat. mate the 2700 carries a centerline measuerment of 7.8 mtrs including pods. i think the difference between your 23 is the pods plus the 2700 has more deck space due to no outboard wells.the beam i think is the same at 2.55m and wayne hennig has added a tunnel wave piercer.mines powered with 2+150 merc optimax's i'm really happy with the boat's performance top speed 38knts with 560liters on board 4 blokes and full water and gear but where it really counts for me i usually cruise at 25-27knts sitting on 3700-3900rpm very comfortable ride in any direction exept head on if seas are getting up(which in my experiance is every boat i've ever been on going into a head sea at speed} oz scott nothing wrong with the old vag mate;of course you've got to compare apples with apples . :'(you pay a premium for that ride{want to swap fuel bills} :'( ;D

[ozscott]

fair enough mate!! ;)

[Kerry]

Kerry are you saying that I should go smaller on the props? and why...

What are you running, what is it powered with, what sort of rpm are you pulling at WOT, what's your cruise speed and at what rpm?

[Kerry]

....but where it really counts for me i usually cruise at 25-27knts sitting on 3700-3900rpm very comfortable ....

Those revs at that speed for an engine with a max WOT of 5750 tends to indicate overproping? What is your max WOT?

[23-sharkcat]

My cat is powered by twin 470 mercruisers @ 170hp each

I cruise at 30knots at about 3250rpm

WOT @ 4200rpm

they are good on fuel as they run on unleaded. I us about 20-25ltrs an hour each. which for a bout of this size and weight is really good.

absoutley awsome out of the hole due to the torque of these big engines.

[saurian]

Be careful 23 ,
Kerry will bring out the prefix before comment rule.
Who cares you guys get out there enough to know what is going on .
Soulfish sounds like joy. My fuel bill isn't quite yours but I wouldn't save
fuel to get hammered.
Ta.

[soulfish]

kerry ,around 5450-5500 i'm no expert mate do you think that's ok ? i've had the boat 4 months ,bought it second hand.it was set up by noosa cat '

[JB]

Out of interest what were the other 3 vessels you were comparing your Cats performance too?

Wasn't interested in your comments saurian, the question was in regard the actual original post, too Antony!

So saurain don't get up on your tippy toe, absolutely nothing to do with you!


Ha, good ol kewwy at it again #::) #wat a weapon #lol

Nothing to do with you either you fool! Just JB mouthing off as usual and saying absolutely nothing, get a life you clown! Be constructive JB otherwise simply pull your head in.



hahahaha, ZZZZZZZZZZZZZ better up the drag this ones running hard!! LMFAO

[bannana]

Soul fish. How the hell are you snapper basher. Good to see you finally found a new name to call yourself. After all Lockey was quick to steel your last name so i thought it would be fair game to pinch your other well known name BANNANA. ;D ;D ;D Mate got to give you a big rap on your efforts on Sunday. I know you've had a good week at work after landing 2 big knobbies. The missus just wanted to say thank you for sharing , as the one you gave me #will probably feed us #all week. As far as your 2700 noosa cat goes, you proved me right when you bought it. I test drove the dominator and the noosa cat and #in my opinion the dominator is that far behind the noosa cat it;s not funny. I have owned a 680 AMM, 680 Haines as well as a 680 seafarer voyager and although in certain conditions they rode as well as yours , I still #know what I'd rather be in, especially #fishing offshore in 20knts or worse.

[Kerry]

My cat is powered by twin 470 mercruisers @ 170hp each

I cruise at 30knots at about 3250rpm

WOT @ 4200rpm

they are good on fuel as they run on unleaded. I us about 20-25ltrs an hour each. which for a bout of this size and weight is really good.

absoutley awsome out of the hole due to the torque of these big engines.

I/O's on most vessels don't really have the same issues as most outboards and are a little bit more forgiving. Still one should compare what the engine manufacturers WOT spec is compared to what you can achieve.

4200rpm? I'm guessing would be a little bit below what most I/O's of this era should rev out too???? maybe only a few hundred revs in it? maybe not worth worrying about??? depends!

Regards, Kerry.

[Kerry]

kerry ,around 5450-5500 i'm no expert mate do you think that's ok ? i've had the boat 4 months ,bought it second hand.it was set up by noosa cat '

Just becasue it was setup by Noosacat means bugga all. If you are satisfied with 5450-5500 FULLY LOADED, FULL FUEL, FULL GEAR, Typical person capacity etc etc then it's getting close to 5750 max WOT.

If 5450-5500 is achieved at the other end of the load scale (Lightly loaded etc) then I wouldn't be happy with those revs.

My main focus is with the 3700-3900rpm,which for most outboards is no mans land, that rev range transition (3500-3900/4000) where most outboards starts to hit the 2S power band and the rev range (3500 +/- 200 or so) where 2S's just luv fuel.

Regards, Kerry.