John,

All flat bottom wing planes want to climb as more power is applied and airspeed increases. The answer to that is down thrust, down trim or positive incidence in the stab to hold the nose down. In other words, decalage and thrust line will take care of the flight trim.

Note that the angles I stated are in relation to the hull CL on a flying boat or the float CL on a float plane. The flight trim is a different ballgame. The idea is to get the model "on the step" and planing on top of the water. A semi or symmetrical wing takes even more incidence angle
than a flat-bottom relative to the floats. The model needs lift from the wing to get on the step.
All of this is can be found on several web sites and books on rigging a float plane. I got the basics from reading Chuck Cunningham, a recognised authority on float flying.

BTW, in my experience, it's easier to get a float plane off of slightly choppy water than off of mirror smooth water. The full-scale guys sometimes taxi in circles to get the wave action going before takeing off.

You and other posters on this thread have made some excellent points. I'm just suggesting that if all else fails, it's easy enough to shim the wing up a bit and try it.

Cheers,

CR