Low speed planning performance.

[BigE]

Hi guys

Looking at repowering a signature 1750l something in the 115 - 150 hp range. I would like to get the boat to hold on the plane at a lot lower speed than it does at the moment, somewhere in the 20kph range would be nice. looking for a comfortable ride without hammering the bejeuses out of everything. (mainly my back).

So what I'm asking is how does motor choice affect the low speed planning peformance of this type of hull and what should I be looking for to improve the boats performance in this area. How do props foils engine weight and tabs affect low speed planning performance.

Please go easy on the 4S Vs 2S as i real have no preferance on engine type I'm more concerned about ride comfort.


Thanks
Big E

[Chimo]

Hi Big E

From experience with a number of boats over the years foil and tabs each add positively to improving low speed planning.

If you buy tabs Lenco or Bennett with a flat plate as the tab will help without adding to drag especially when they are fully up ie not engaged.

The lighter the motor for a given HP, the easier it is to get the boat's bum up.


Cheers
Chimo

[Spaniard_King]

Go for the biggest CC's for the HP Intended which will produce the highest amount of low end torque and prop it high into the rpm range this will ensure the engine will perform down low as well.

[BigE]

Thanks Chimo & Spaniard King.

Is there any referance for which outboards make the most low down torque, or any where you can obtain outboard torque figures? I don't think i have ever seen them.

BigE

[TheRealAndy]

Planing ability is more about hull design and trim than engine performance. You cant change the planing speed of the hull. A flat hull will plane easy than a deep V, but the ride is going to be crap. Then engine might help you get on the plane quicker, thats about it.

[BigE]

Thanks Andy.
I'm not trying to turn a pig into silk purse, or reinvent the wheel, But i am trying to max the low speed planning performance as much as possible, as with all things I'm sure there are things that will help and things that will hinder the boats performance in this area.

BigE

[Smithy]

If there is such a thing as "usable torque" 4 strokes have it and 2 bangers don't. The Etec advertising rabbits on about how much torque they produce but in the real world a 4 stroke will keep you on the plane at whatever rpm you want, especially if you have a foil on it and the 2 stroke will want to jump up and race away on you once it gets the hull planing. Same downsea, the revs will go up and down a lot more on each wave or swell with a 2 and may only change 300rpm or so with a 4 stroke. My motor for instance I am usually running at 4,200 rpm to keep it up on clean plane and a big swell can knock me back to 3,900rpm but I will still keep on the plane without touching the throttle then I might race away to 4,200 on the down face of the swell but it won't race away like a 2 stroke would have.

[Spaniard_King]

Andy,

low and mid range torque is what outboard manufacturers are all after, it plays a big part in low speed planning. The more torque down low an engine has will hold a boat on the plane at as lower speed. As Smithy has suggested the 2 stroke tends to fall off the plane earlier than the 2 stroke.

[marty666]

add a foil to the outboard with tabs and more blades on the prop to help lift the bum too if you are not looking for top end possibly going to a 5 blade might be some thing to look at.

[Crocodile]

Hello BigE,

I used to have a foil but now I have wedges between the outboard and the transom, this allows the motor to really trim under a lot more.
I have measured with the GPS that the boat will now plane at lower speeds than with the foil.

On the subject of 2s versus 4s I have just bought a new motor and went for a 2s partly because the 4strokes that I drove were awful things that had no low-speed power at all and simply fell off the plane.
I can stay comfortably on the plane at 3000 RPM for 12 knots(GPS).

If low speed planing is you thing go for the lightest 2s motor that you can find.

[Captain Incredible]

Croc is on the money for staying on the plane. Under tuck is real good but be careful going downhill.

Also when propping go for a smaller pitch but larger diameter prop which will deliver more thrust down low. Check out SOLAS PROPELLORS and talk to Steve as delivery of the "torque" through the prop is essential.

The real issue as I see it is your bad back. Your hull is not a bad thing but not particularly bouyant aft (please don't take this as a personal insult) so there is going to be a problem keeping it on the plane with anything on the back.

How about a bit of divergent thinking, keep your current engine and buy a hydraulic seat? After having a hip replacement I bought a "Marine" hydraulic seat for my centre cab and now only drive seated. If it could cook I would marry it. I can tolerate far higher speeds than I could before. Instead of taking the bang out of the boat I took the bang off my hip.

Just a thought.

[swof63]

If you want real dyno power and torque figures, you can get them from the Californian air research board somewhere here http://www.arb.ca.gov/msprog/offroad/recmarine/recmarine.htm

I have noticed tabs make a big difference. I have Lenco tabs and tabs undeployed will hold plane down to 16-17 kts, tabs deployed planes down to 12 kts easy.

Cheers
Craig

[bustaonenut]

Also when propping go for a smaller pitch but larger diameter prop which will deliver more thrust down low. Check out SOLAS PROPELLORS and talk to Steve as delivery of the "torque" through the prop is essential.



Tried that on a 6m allison angler with 200hp 2 stroke. Turned out to be a real dog dieing up a big swell then running away again, was always on and off the throttle. The prop was a 17p and i think around 15.5" diameter. Installing a permatrim helped but on a lighter load, once the boat was heavy would have the same problem.

After a bit of reading we tried out a 4 blade prop and that is what is still on the boat, best thing ever can sit on the plane at 2800rpm and rarely have to touch the throttle, the motor even sounds differant like there is no load on it,

Fuel went from about 140-150ltr for 70nm trip to 130ltrs

[johncar]

Hi guys

Looking at repowering a signature 1750l something in the 115 - 150 hp range. I would like to get the boat to hold on the plane at a lot lower speed than it does at the moment, somewhere in the 20kph range would be nice. looking for a comfortable ride without hammering the bejeuses out of everything. (mainly my back).

So what I'm asking is how does motor choice affect the low speed planning peformance of this type of hull and what should I be looking for to improve the boats performance in this area. How do props foils engine weight and tabs affect low speed planning performance.

Please go easy on the 4S Vs 2S as i real have no preferance on engine type I'm more concerned about ride comfort.


Thanks
Big E

Well all the things you mention will help,
Hull design is a big factor but you can help it by:

Minimising the engine weight vs high mid range torque curve at 3000 - 3500

Tabs are an advantage on any boat in this range.

A foil could be helpful but I would try everything else first. I just say that because it not good to add stress to your engines cav plate and mountings unnecessarliy if everything else is wrong and fighting against it.

4 blade prop at a lower pitch rather than high should help. Your engine should be able to easily reach full RPM.

Well balanced weight distribution and minimise the overall load as much as practical.

It does amaze me how many buyers and boat testers, dealers focus on how fast a boat can go in sloppy conditions when for most of us it really is more important how slow it can comfortably go.

The last boat I bought I insisted on a water test and yes it was a good day for it being 20kn plus conditions. The sales rep took it out and straight up to 5000 or more RPM and we were flying across the waves with the occasional bang but not bad. He was surprised when I took the wheel and said "that's all good but I want to know how it handles at 3000RPM".
Happy to say it went very well and was still planing nicely at 12kn and under 3000RPM and I was giving it all sorts of manouvers in all directions and trim to try and trip it up but no worries.
Only after that I tried a bit of higher speed stuff which it handled just fine but it's not often you can go fast offshore so it's not a priority for me.

good luck with it.

[Noelm]

OK, as someone who has had a thousand debates/arguments on whether 2 strokes are better than 4 strokes (and I have argued on each side) I have had the same boat with standard carby 2 strokes, HPDI 2 strokes and 4 strokes, for smooth "power delivery" the 4 stroke has it all over a 2 stroke, the 2 stroke is a motor that loves RPM and will be a slug at low RPM and will (as mentioned) at times bog down, and require a hand full of throttle, then get up and going and need the throttle pulled back, a 4 stroke does not suffer this "feature" anywhere near a 2 stroke, for what you want, a suitable HP 4 stroke will be your best bet.

[cormorant]

Andy,

low and mid range torque is what outboard manufacturers are all after, it plays a big part in low speed planning. The more torque down low an engine has will hold a boat on the plane at as lower speed. As Smithy has suggested the 2 stroke tends to fall off the plane earlier than the 2 stroke.

If the 2 stroke was propped for performance at that those revs for low speed planing rather than top end it wouldn't suffer that. It would suffer somewhere else unless hull and prop were 100% matched - yeah that rarely happens. A 2 stroke has more torque and reserve torque at just about all revs( especially low ) in general but how it is propped ( what gearbox) and used is the other half of the problem. Since the torque graphs for comparison use revs over torque one being higher than teh other at specific revs means nothing unless the prop and hull can use it effectively. If manufacturers would like industrial diesel motor manufacturers put out decent data it would be a help in motor selection for specific purpose as a general outboard is a compromise for different uses.



A 2 speed gearbox would make all the difference or a prop that pitched out at really high revs to give that top end ( yep they exist- 2 speed props for ski boats )
Basically a lot of motor issues are actually prop issues . Some hulls are not designed for a slow plane with the boat at a good attitude.

The way people load their boat up with extra weight these days I'm amazed some plane at all. :-X Assumably later hulls designed with 4 strokes in mind and with live bait tanks from teh factory have taken that into accont but retrofit boats?

A prop is always a compromise and very few people prop their boat for mid range performance as they don't want to lose their top end ( wank) performance that is used for possibly 5% of engine hours unless ski racing.


Still amazes me the same motor with the same ports , cam is used for both skiing and offshore lugging and yep electronics can fill the gaps but that comes at a price.


Low speed planing - longer hull- hull extensions, pods, trim tabs , permatrims can all help if set up right.

People above have covered most all of the options. 4 Blade props that add stern lift can help but they can cause handling issues at higher speeds if it is overdone.

Ok so who is for a diesel with a 2 speed box or variable prop??

[Micadogs]

Hi Big E,

I installed trim tabs on my boat and my 'slow plane' speed dropped from approx 25-28 klm / hour to around 16 - 19klm / hour. They also straighten the boat from wind list which makes it a much softer ride. My 8 month pregnant wife and a 2 year old slept all the way home from tangalooma to manly in a 20 knot wind - no banging and crashing etc

Trim tabs made a huge difference to my boat - both slow plane and slapping.

FYI - 5.5 metre fibreglass boat with a 115HP 4 stroke

Regards Adam

[TheRealAndy]

Andy,

low and mid range torque is what outboard manufacturers are all after, it plays a big part in low speed planning. The more torque down low an engine has will hold a boat on the plane at as lower speed. As Smithy has suggested the 2 stroke tends to fall off the plane earlier than the 2 stroke.

How? The only way I can mentally picture this working is by using torque to somehow provide extra lift? If this is indeed the case, then best way would be to use 2 engines with foils?

[Noelm]

twin engines will maintain a slower plane.

[Chimo]

Hi Corm

Yes please, I'd like a diesel with a 2 speed box or variable prop for when I have to change over from my twin 115 s outboards but I suppose you need me to change boats too?

Cheers
Chimo

[TheRealAndy]

twin engines will maintain a slower plane.

Ok, so then to get even more lift from your outboard, would you not also be better off using high thrust props/gearboxes (knowing that you will lose top end speed)?

I am still not sure I get the whole concept just yet though, to me it still does not make a whole lot of sense. Everytime I picture it in my head someother concept comes and destroys it for me :-?

Also, I am not sure that the whole 2 stroke v 4 stroke thing would make a whole heap of difference. Surely the torque at lower revs is not that significantly different to make a big difference. I would guess that prop selection would be much more important.

[Jabba_]

If there is such a thing as "usable torque" 4 strokes have it and 2 bangers don't. The Etec advertising rabbits on about how much torque they produce but in the real world a 4 stroke will keep you on the plane at whatever rpm you want, especially if you have a foil on it and the 2 stroke will want to jump up and race away on you once it gets the hull planing. Same downsea, the revs will go up and down a lot more on each wave or swell with a 2 and may only change 300rpm or so with a 4 stroke. My motor for instance I am usually running at 4,200 rpm to keep it up on clean plane and a big swell can knock me back to 3,900rpm but I will still keep on the plane without touching the throttle then I might race away to 4,200 on the down face of the swell but it won't race away like a 2 stroke would have.

I can't vouch for any other E-tec but mine on my rig, I dont get any runaway unless it is a real steep wave comes along and stands the stern up high...

However if I have not trolled for a long time (between seasons) the motor will for the first 5-10 minutes (when running with the swell) will want to run on.. After that the EMM learns and adjusts to my driving style or trolling and very rarely will I need to make another adjustment to the throttle, unless I get a biggy stand the stern up. But even then a 4st will run on also...

My prop made a big difference also.. My original Viper was great for high speed, but not so great offshore or slow planing..

I now have a Rebel, it can hole a slow plane very well at 2500rpm on smooth water and 2800rpm offshore.. Top speed lost 2mph with this prop, but erveywhere else is so much better...

[oldboot]

Apart from very small changes that foils, trim tabs and engine choice can have.

There is only 1 thing that will consistently improve low speed plaing on a given hull.......and that is weight distribution.

All the other things.....the slower you go the less influence they will have.

weight distribution will effect hull performance at every speed.

Include in weight distribution weight reduction.

prop choice and all that will have very little effect on what speed the hull will plane at.....all it may do is allow a more consistent low speed to be maintained.

for example.
My BIL's little savage with 30HP on the tail and no trim facilities.....with 3 aboard, moving the two pasengers forward a couple of feet forward makes a huge difference to how easily it will plane and how slow it will plane..with one aboard up front, it will stay on the plane at rediculously low speeds..it is sweet, well ballanced and light.

My Stacer with 60hp a pod, electric trim and foils on the other hand was far too stern heavy, realy had to climb out of the hole and would drop off the plane quite early.
All because it was heavier and poorly balanced.....hopefully better soon.;D


before you start spending serious $$$.
Look at how the boat is loaded and perhaps move some things like people, eskies, batteries and fuel tanks.

cheers

[Noelm]

high thrust gearboxes (that is lower gear ratio) enable a bigger prop to be used, and turned slower, which does result in better low speed plane (kind of like your car in 1st or 2nd gear) but it is a compromise (as always) 2 strokes do have a very defined "power band" and some will go like the clappers once this band has been reached, but will die off if the RPM has dropped just a tiny bit below it, anyone who has ridden a 2 stroke dirt bike will know what a power band is, thats for sure.

[bigjimg]

BigE I have fitted a Stingray foil,similar to a permatrim,and can maintain planing at 10knt.Made a huuuge difference to the handling,all for the better,and keeps the bow dead flat when getting on the throttle.Very cost effective alternative to trim tabs,I was considering them but now I won't bother.Took me 15 minutes to install and no holes to drill.Jim

[Tickleish]

Hey Jim,

Where did you get your foil from & how did you not have to drill holes?

PS I've got the same donk as you.

[bigjimg]

Hey Jim,

Where did you get your foil from & how did you not have to drill holes?

PS I've got the same donk as you.
I got it from Whitworths,was $249.You take the cavplate anode off and then the foil slides on over the cavplate.All that needs to be done is bolt the anode back on into the recess on the foil which clamps the unit onto the plate,job done.Jim

[marty666]

you can buy the same foil from cabelas for the $100 mark plus postage which would be half the price here that is where i am going to get mine from

[robothefisho]

Props WILL make a HUGE difference to slow speed planing ability.

Suzuki 140 plate boat 3 blade, planed to around 12 knots maybe a little less.

Same boat, 4 blade prop same pitch, holds plane at 7 knots.

The difference is the thrust delivered. Mind you planing at 7 knots is not at all economical as it's still revving at 3000 somthing.

[BigE]

Lots of information to sort through , thanks for taking an intrest, I would like to hear more opinions on 4 blade props pros and cons. and about an engines ability to hold on the plan without to much throtle jockey work , Im a set and forget and enjoy the ride type of boater.

So far I'm thinking 4s with cubes some wedges and maybe a 4 blader.
any thoughts on this combo?

BigE

[BigE]

Old boot i like your thinking, common sence approach. thanks.

BigE

[BigE]

Noelm

Twins you say..... I like it (the wife has just banned me from ever speaking to you again). but i dont think it is in the budget.
thanks
BigE

[BigE]

Hi Big E,

I installed trim tabs on my boat and my 'slow plane' speed dropped from approx 25-28 klm / hour to around 16 - 19klm / hour. They also straighten the boat from wind list which makes it a much softer ride. My 8 month pregnant wife and a 2 year old slept all the way home from tangalooma to manly in a 20 knot wind - no banging and crashing etc

Trim tabs made a huge difference to my boat - both slow plane and slapping.

FYI - 5.5 metre fibreglass boat with a 115HP 4 stroke

Regards Adam


Adam
that sounds about where i want to be and your rig sounds similar to mine. what hull / motor do you have

BigE

[bigjimg]

you can buy the same foil from cabelas for the $100 mark plus postage which would be half the price here that is where i am going to get mine from
$146.00 actually and whatever the shipping cost is.XR111 Stingray.Probably get up to somewhere around the $180-$190 approx,they're pretty bulky item packaged.Jim

[Smithy]

I reckon your thinking is going ok. Wedges will help and getting rid of weight from the arse and trying to put it in the nose. I am not a fan of Stingray foils. They can give some boats handling issues. The prices quoted here are scary too. I remember when they were like $130 in the mid '90s and the SE Sports were about $90. Must be inflation. The best with no vices are the Lazilas LZ foils and they are the cheapest to boot. Usually $40 from BIAS.

[Captain Incredible]

Just be careful with moving weight forward to keep a boat up on the plane. A good mate who should have known better had a good 30 footer. He stuck 60 metres of chain in the bow to lift his engine rams out at rest to minimise corrosion and in the process turned a reasonable sea boat into a pig, bow down and a broacher. When he got rid of the chain it went back to being a good boat.

Weight forward is good to get up on the plane as long as you can then move it back if needed.

Some boats are actually fitting fixed hull extensions to better float heavier motors. These can be either fixed flat metal or foam filled hull extensions which double as boarding platforms.

Do consider a hydraulic seat or padding on the floor if you stand up driiving. Every little bit helps in the comfort stakes.

[marty666]

$146.00 actually and whatever the shipping cost is.XR111 Stingray.Probably get up to somewhere around the $180-$190 approx,they're pretty bulky item packaged.Jim

they must of been on speical they other month but the SE 300 with attachment option $135 to your door from them

[Micadogs]

Hi Big E

My boat is a pursuit 5.5 metre fibreglass halfcab, it has a 115HP mercury 4 stroke motor.

Read some of the other posts on trim tabs in this forum. They are the way to go.

Regards Adam

[johncar]

Lots of information to sort through , thanks for taking an intrest, I would like to hear more opinions on 4 blade props pros and cons. and about an engines ability to hold on the plan without to much throtle jockey work , Im a set and forget and enjoy the ride type of boater.

So far I'm thinking 4s with cubes some wedges and maybe a 4 blader.
any thoughts on this combo?

BigE


BigE, the 4st is possibly a good choice but if going for bigger cubes the weight could be a killer, keeping the weight on the transom and to the whole stern is important to maintain lower planing speed.
A good rule of thumb would be to look at the boats original recommended HP and transom weight and go somewhere midrange.
I wouldn't think that you would need wedges on a HS as it should be OK standard.
A relatively low pitched prop say a Solas 4 blade or similar should be a help.
If you have any cash left over I totally recommend Tabs regardless.

[oldboot]

Just be careful with moving weight forward to keep a boat up on the plane. A good mate who should have known better had a good 30 footer. He stuck 60 metres of chain in the bow to lift his engine rams out at rest to minimise corrosion and in the process turned a reasonable sea boat into a pig, bow down and a broacher. When he got rid of the chain it went back to being a good boat.

Weight forward is good to get up on the plane as long as you can then move it back if needed.

Some boats are actually fitting fixed hull extensions to better float heavier motors. These can be either fixed flat metal or foam filled hull extensions which double as boarding platforms.

Do consider a hydraulic seat or padding on the floor if you stand up driiving. Every little bit helps in the comfort stakes.


The focus has to be upon gettng a well balanced boat.............I don't think putting lots of weight in the nose is a good idea at anytime......we should be trying to get most weight as close to the centre of flotation as possible.

remember the centre of flotation on most plaining boats will be arround 1/3 forward from the stern..and when properly on the plane most of the front 2/3s will be out of the water.

excessive weight in the bow will have a pendulum like effect.

anyway a nose heavy boat will not plane efficiently either.

If you can manage to get ya boat sweetly balanced, just about everything about it will be better.

cheers

[BigE]

Thanks guys, l will keep an eye on the weight as well. any other thoughts intresting consideration on weight is that a 115 hp 4 stroke has the equivilent weight to a 130 - 135 DI 2 stroke which would have the most torque in the lower planning speeds?

Bige

[Captain Incredible]

Big E, Looking at the pics in your avatar, the problem you will have is not with the weight of the outboard. You real problem is not putting too many of those big red suckers on the deck or you are gunna sink! (LOL)

[BigE]

CI
It's a tuff job ....... but damn it someone has to do it!

Once i sort the new rig out there will be plenty more of them.



BigE

[bigjimg]

A simple thing to do is look at the boat while at rest in some smooth water.You will soon see if it is heavy in the bum.Also run a 2m level along your hull and note the angle in relation to your cavplate when the motor is trimmed full in and note when it is parallel as you trim out,mine reads 1.8 on the trim gauge.Sometimes a foil is the best option,try getting trim tabs on a 580 sig without a lot of stuffing around and expense.Jim

[BigE]

.........................................

[BigE]

Good tip Bigjimg never thought of set up the trim with a level.

Any other thoughts.

[deckie]

My first thought would be process of elimination starting with what is always the best option..something that doesnt cost anything. Too easy to get on a merrygoroud searching for what you;re after...which is what we'd all like really coz u get far better fuel figures, less work with the throttle and that feeling you;re at the perfect speed u can just go all day.

My first port of call would be experimenting with weight but make it simple...100kg sticking its head out the front hatch when he normally wouldnt will tell u a lot. Lets face it..the bottom line will be how it performs in a following sea wont it...if u do anything at all weight wise this will be the bottom line and even if she planes easier in flat water you probably still cant do it anyway if it screws with performance/safety offshore. Even with the nose trimmed right up thou might find she'll still have a tendency to dig in and drift off line downhill making u feel a bit less secure/safe. Who knows tho..if she still feels secure that will likely go a long way to planing at lower speed inshore. No point experimenting in flat water. If you have dual batteries on the transom there's 45kg for starters that u may be able to move...the weight transferrence of those alone is far more than their static weight coz you;re actually adding it onto fwd weight whilst taking it off the back. Wouldnt put them firther fwd than just in front of the helm tho and not a small job...but can be as simple as moving what u already have plus some new cables and extra solid mounts.

After trialling weights a cpl of times i'd be thinking hydrofoil next before going to pricey stuff. Some arnt big fans of them coz thy believe they adversely effect their hull in a following sea but they usually do seem to add poke out of the hole and do seem to help plenty of 5mish rigs hold plane at lower revs. Wouldnt bother with any that have a small surface areas tho....plus you'll need to wade thru a minefield of brands/ types. Certainly worth trying before trim tabs i reckon.

Third thing i;d try is propping, but if you;re anything like me when you ring mr propellor i guarantee you;ll end up with a shiney new prop regardlless;D. Tell them exactly what you;re looking to achieve..i.e one thing only. To be honest tho i really dont think you'll achieve more than a marginal gain doing this...helpful but probably not what you;re really after.

Who knows...the answer might be a combo. Wouldnt rush out investing in trim tabs on a 5-5.5m rig. Weight is free to test..do that first...modern rigs carry far far more weight down back and even tho designed for it, it must at least effect some aspect of performance when planing.

Lastly but definitely worth trying is those bloody pedestal seats most have. Rip em out or at least get shock absorbing ones. Its just not natural to have your arse pounded i reckon :-X. I've been thru one back operation and wont stick my bum on any seat whilst underway anymore. Grab some cheapo eva foam gym mat about 20mm thick and put it between the seats...steer with the right hand whilst standing up for a bit and just let your knees be rubbery with the ups and downs....bewwwwdiful ;D. You soon learn how to float with the bumps ;D. If u like it think about moving the helm seat back maybe 20cm so u can steer standing up or kind of leaning against the seat bolster like half standing/half seated. With a nice comfy helm pad you;ll be shocked just how much more comfy things are and your back will thank you.

[Jakers 69]

Hi guys, just bought my first boat and are a complete newbie.
Bought a Haines Traveller TC 200, zuki 175 and some extras, still fitting S/S extras, it sounds that to fit trim taps is not a bad thing at all.
What make?
Cost?

Thanks for all the input on Ausfish, I must have spend hours on it already.
I am from the Gold Coast, and also would like someone with local experience to aid me into confidence , and maybe take me threw the process from launch ...

[Chimo]

Jakers

We are all here to help, there's no such thing as a silly question ....

Cheers
Chimo

[BigE]

Thanks Deckie some good advice there. I with ya on the pedstal seats! Moveing the batteries looks like a bit of a mission, but I am thinking about the esky, looks like i could get a 100lt job right in the centre between the driver and passenger and another 70 lt esky or fuel tank between the bunks. that a lots of weight forward and down low, and it's movable if it affects the handling in a negitive way.
BigE

[adamleah]

Ian,
Thats exactly where I had my eskys / tackleboxes when I took the old girl out...... it also added another place for a mate to sit also between the two up front so we could all gas bag whilst driving ..... I never really noticed the lag much when I had her, except when lifting skiers..... which took a bit of effort.... I didnt really go much slower then 30 knots though as I always found it easier in the bay chop to bounce across the waves instead of going up and down them as the bouncing at higher speed allowed the kids to sleep still but if trying to bounce around at lower revs made it a lot bumpier........ This prob wouldnt work in bigger seas though as you would get a lot more airborne?