The hood on that lens is built in an integral to the construction design, in other word, permanently fixed, there is no reason why it should be removed, quite the opposite, in shallow water, with the sun beaming down, it will help reduce flares.
Merci Jean! Meme-ci je marche avec un Subal! I'm working in a Subal housing with a 5D mk2 and I'd find any alteration too radical right now. But if I contemplate a change I'll know whom to call...and I've delighted in your advice here, for which many thanks! J Duvall