I am bad with gamebooks and even worse with tabletops. I grown in Russia, remember?
There wasn't anything like that here.
On the plus side, I am fond of Fighting Fantasy gamebooks, so I can check them (in electronic format). For example, vol. 19 - Demons of the Deep - have underwater adventures, with dolphins, fishes, Atlantean... and sword instructor Cyrano the Swordfish. Is it?