Hello,
Thank you for your answer.
I don't know at all about the center of gravity but the idea is very good, I hadn't thought of it.
Usable photos are really very rare, in fact I only have this one...
They had to weigh heavy these big floats and yet she flew as long as the terrestrial version (3h from what I read on the internet) .. and with one tank less.
With or without plaque your work is remarkable.
Best regards.