I've been doing a bit of this as an added option for my modeling work. A lot of models are really into it, some aren't, but most jump at the chance to have their portfolios stand out
I originally got a Ikelite Housing for my 5DMKII body, but have since moved to the Aquatech Housing for how much simpler it is to use and set up. Ikelite offers much more adjustability to the camera once in the housing. You basically can still adjust every button on the camera while it's in the housing. The Aquatech is more of a surf housing, and you set the camera up before you put it in the housing, and then just shoot with those settings.
The Ikelite is a great housing, it's just geared more towards diving, and I'm doing what you asked about, just shooting at surface with available light
I'm actually going to put the entire Ikelite Package up for sale if you're looking to get one. And it'll be a LOT less than buying new. I also just sent it back to Ikelite to have them pressure test it and they ended up replacing the housing due to a slight crack in it, along with all the seals around all the buttons, so you're basically buying a brand new housing
Shot with the Ikelite Housing