hi all
a quick explanation :
John 54 - the hull you have is obviously based on an offshore power boat hull of the Surfury type hull. Medium to deep 'V' section.
Normally, MTBs, Picassa, SeaQueen's the hull's 'v' viewed from the stern is shallow to medium. Meaning, from 0 degrees flat from chine to chine, up to 13 degrees from keel to chine.
Deep Vs go 13 degrees up to about 17-18 degrees.
The shallow 'v's vessels come onto the plane quicker and with less power. However, in the life size boats, they were prone to slamming in heavy seas. To counteract this, they adopted the type of hull which you can see in the Picassa type hull. This is where you have a very narrow entry point at the bow and it flares out to the medium 'v' approximately half way along the hull.
Now, when the guys were doing the offshore power boat racing in the 60s and 70s the flat 'v's hulls tended to self-destruct. So the next step was to increase the angle of the 'v' from 13 degrees upover. This requires a lot more power to bring the vessel onto the plane. You will notice on the hull you have, John54, the bow cross-section profile is not narrow, but, full 'v' and this 'v' carries on at the same angle all the way on to the transome.
You also have 'spray rails' on your hull. The original idea of these was to reduce 'wetting areas' on the hull. In other words to throw the spray away from the sides of the vessel and therefore reducing 'water-drag'.
Now we have explained a little bit of the theory side of it, to try and solve the problem.
The hull looks a fairly substantial built fibre glass hull and it looks as though its been used in its past life with an I.C. engine for some sort of off-shore racing.
Suggestion of putting trim tabs on the back, may well work, but I doubt if it will. The reason I dont think it will work, is, it will bring the bow down and therefore increase wetted area to the hull. What you must do is try and keep the weight of your batteries down low, by using NiCad packs and also, as has been mentioned, use a bigger prop and water-cool the motor.
What you should be aiming for is what is known as quarter the hump ::) sounds rude but....what it actually means is - if you can imagine a see-saw, the crest of the wave, where the boat is planing on is the 'A' frame support and the plank where you sit on, is the boat.
The bow of the boat should be 3/4 of the length away from the centre of the wave, so you only have your stern 1/4 in the water.
Hope this helps you - its a lot more difficult to explain than I originally thought
can draw a few pictures if you get stuck.
aye
john e
bluebird