RE: Where should the step be?
I have always put my step about 1/2" behind the CG and never had a problem. I just recently got a Goldberg Cub (77.5" span) with the Goldberg floats and they are set up to Goldberg specs which is the step 1/2" ahead of the CG. I have found this to work even better at least on the Cubs. It handles well and lifts off the water without the the "pop" or "breaking" off the water some of the float planes will do. I will start experimenting with the location of the step on my future float planes. I currently have a Sig 1/4 scale Cub I'm recovering and it came with a set of Sig 1/4 scale floats made for it. I am going to look for the location of the step on those to see if they are set up like the Goldberg ones.