Glass bottom boats
Years ago, I was asked to bid on constructing a glass bottom boat for Avis Rent-a-Car for coral reef tours on Guam. I had zero experience with such, and there were none existant in the Western Pacific, but some parameters suggested themselves: 1.-The glass has to be below the surface. 2.-The passenger load could vary between six and 40. 3.-Draft had to be minimum possible to make max reef accessible. 5.-Boat had to comply w/ USCG and ABS regs. Result: Catamaran hull with variable depth viewing boxes that made very slight contribution to displacement, and posed no danger if shattered.