The instructions recommend to install the float in alignment with the wing rib end. I've seen pictures that show two differents positions as pictured here. Which one is right ? Left or Right picture ?

I would do it like pic #2 because you can center the float over the rib. In Pic #1, the rib is along one edge of the float.

I would agree with Mike, knowing that most flying boats have water issues when their tip floats are mounted all the way out on the wingtips(i.e. Seawind), I would move it in like #2.
Good luck,
Curtis

Ok, thank you guys. Exactly what I tought but wanted to get someone with more experience comment.

Thanks,
Séb