Floating Dock with Upper Deck

[johnwow]

To the point, we do a lot of dock designs for a local lake but have come across one where the owners are insistent on pulling off their roof on their existing floating dock section and replacing with an upper deck. We've done them before, but most always they are fixed with a floating or fixed slip below. Only done a few all floating with upper deck but typically have wider fingers for stability. This existing dock has only 4' wide fingers .. the floats per calculating buoyancy would require at least 32" deep floats. There are posts on each side of the fingers and can brace those to keep the fingers twisting but my real concern is with the depth of the floats and the risk of them kicking out if, say, a large crowd and a lot of weight is on top of this deck. Anyone here have some experience with these deep floats?