This is a depiction of actual "snuba" ( www.scuba.com
like scuba, but done with the tank in a raft on the surface) as done from the 52' Holo Lea Kai ("Free like the Wind", in Hawaiian) out of Ko Olina Resort on the southwest side of O'ahu island, Hawaii.
Notice the staircase that drops to the water's surface, in the bow area between the hulls. Notice also the "sugar scoop" stairs in the stern, the shapely photographer, and the tether rope that ties the instructor/guide to the snuba raft.
I'm very fond of snuba as a way to do "intro" (first time, try-before-taking-a-license-course) diving. Last week was my first time diving in three years, and the first time I'd done snuba as a customer rather than as the instructor.
It was an odd feeling for me, an experienced scuba diver, to be tethered to a raft & to be following a guide... but it was an excellent way for me to try getting back into diving after 3 years away...and being in a wheelchair for the last year. I had a moment of anxiousness at the surface, as I wondered how the increased resistance of scuba air would affect my "new" (i.e., wheelchair-and-heart-failure) body, but the fear faded after a moment and I blissfully did a backflip while descending to the 25' deep reef.
I heartily still recommend snuba for anyone who's uncertain about whether scuba is something they'd enjoy. Ideally, do your first from the shore or in a hotel pool. After that...if you liked it, do snuba from a boat or a scuba certification course anywhere.
And no, I'm not being compensated to say that. I'm a true believer.