will this work?

[rcflyers]

I have a 2.9m inflatable with a Mariner 8hp, it will plane with just me in it but when a 2nd person gets in it won't quite plane. We only use it in calm/river conditions. If I deflated the inflatable keel partially or fully this would make it more flat bottomed and therefore easier to plane 2 up! Anyone tried this before?

[timgoz]

I think the rigidity you would loose by doing the above would have an adverse effect on your ability to plane. If the boat can handle a 15hp that would work IMHO.

Keeping the second person as far aft as possible might help. You would have to have the trim right or you could swamp the stern.

Hope things work for you.

Welcome.

Tim

[marshmat]

Hi rc,
Deflating the inflatable keel, even slightly, would leave a large, baggy and floppy piece of fabric hanging under the boat. This will cause a horrific increase in drag and make it nearly impossible for the boat to plane at all. Your boat's planing performance will be best when the V-keel is at the pressure specified by the manufacturer; any lower and the fabric will flop around and ripple (this wears the boat out very quickly as well).
Where is the second person sitting? Does the boat just stick its bow way in the air when you try to plane with 2 people? If so, move the second person forward. If it rides bow-down, move the person aft.
You can't expect good planing performance in a 2.9 m inflatable, no matter what the power or design. These boats are meant as low-speed tenders, easily deflated and stowed, with performance being an afterthought.

[rcflyers]

Thanks, the 2nd person moved around in various places but the boat either rides bow up and won't climb over the hump or bow down and just pushes through the water.
I was wondering if fitting these would cure my problem?

http://www.maximarine.com/products/lifters/index.html

[timgoz]

RC,

May or may not. Like Marhsmat said, much added resistence from the deflated keel will hamper you.

If you have enough to spend on those additions, save a little more and get a RIB or a hard skiff (preferably aluminum IMHO) and go from there.

Lunds and such are great, sturdy little boats, that are hard to beat. Some of the small all welded (as opposed to riveted) boats are nice to.

Take care.

Tim

[Frosty]

Well i think you should keep it as stiff as posssible.

One of those Whale fins on the outboard will help . I have used one and I have to say that it worked far better than I thought it would.

To be honest I made it too. Just a flat peice of glass fibre about 1/4 in the similar shape and bolted through the cavitation plate.

[ted655]

Trim tab of some sort & more power. May be tough to steer & don't turn too sharp.
OR.... get a lighter girlfriend!