i think its actually a matter of how much u wanna invest in UW photography. If its just a 1-off thing, you could think abt purchasing those instant UW cameras. Some friends of mine used them on my last diving trip and they were quite good actually!
For myself, im using a point and click cannon S1 IS with original UW housing - total cost about $1.2k one year ago so i tink maybe its cheaper now. When i bought the cam, intention already was to go UW photography so casing was a big concern.
I also have a DSLR (D70s) and i don't tink i'll ever bring that underwater, the cost is just to high for me :cry: You can see from the links already given. Add together with the cost of diving too, its like ouch ouch.
Regardless, lights are V.impt underwater otherwise you'll get lots of underexposed pics. You can try saving them with photoshop but i dun have that good experiences with it. The arms of the lights cost hundreds of dollars already and a strobe would set you back about the same amount.
So, really depends on how much you wan to invest in this hobby :sweat: Don't forget rental as an option as well.