There IS a school of thought out there that the top of the float should be parallel to the bottom of the wing--if you have a flat-bottom wing. Another school of thought is that the incidence of the stabilizer should match the top of the float. Dangerous if you have a plane with a flat-bottom wing and the stab is in the wing downwash and mounted with positive incidence. (Goldberg Eagle).

I went reactionary when I built my telemaster, and the wing is a good 5 degrees positive. It works fine, but as seaplane said, tune the incidence for what works on your plane. I set up a super stick with zero-zero once, and it was hard to get off the water without drooping the flaperons.

A couple of degrees is about slap-dab in the middle of the safe range.