Smoky,
Cool job! It is abviously VERY light since to takis without even getting the floats very wet. It looks like you could add some incidence to the plane to get off the water sooner. Drop the tail about 1 1/2" from where it is now. THat's why it gets off so quick with wheels: you can rotate more to get more angle of attack.

Remember to hold the upwind wing down with aileron and MAYBE it won't blow over so much. No guarantees, and once the wind gets under the wing, it's strictly up to God whether it goes over or not.