ORIGINAL: nony
Sure more power will overcome anything, but lets try and finesse what he has got to work with and see if we can get him off the water.
Jim Casey gave a lot of good ideas. I have to agree from the photos that I don't see that engine/prop putting out a lot of thrust..I think there is potential there.
Also there is a lot of spray coming up between the floats..some water drag there somewhere.. Are the floats parallel with each other, and with the fuselage? Are they flat bottomed floats?
Go ahead and finesse him all you want and if he does get it off, he'll probably hate you for it. It appears he is a newbie (I could be wrong) and is probably not good at flying a low powered heavy airplane on the wing so to speak. If he does horse it off, he'll probably stall it immediately after lift off and in the drink he will go. I've seen it many times.
But you fellows continue finessing. Some could probably fly his plane, but not many and apparently he can't.