Sometimes, even now, I have dives where nothing seems to "click" photographically (pardon the pun). I can't get anything the way I want it. Usually, I just fold down my strobes, turn off the camera, and enjoy the dive.
I am completely unable to do that when I have a camera. Despite my best efforts, I am able to dive solely for photography far less often than I would care to, and consequently, when I do, I need to find something to shoot.
The hardest part for me with photography has always been getting away from the "obvious" shots and going for the truly creative, unique images. A lack of any kind of creative training in my background contributes to that. So if I try to avoid the obvious shots, I end up with a blank.
My solution is to apply a great tip by Freeman Patterson in one of his books - find one patch and shoot it. Any patch (throw a hoop at random, for example, and use the area within the hoop as the patch) and take 20 or 30 or whatever different photos of whatever you find in it. This forces one to think differently. I apply a variant of that to underwater work. Usually, my trick in such cases is to find something - anything - and spend the whole dive shooting it, experimenting with angles, lighting, etc.
To the OP, I would recommend a variant of that - go into a pool, take something negatively buoyant to the bottom and spend a whole dive shooting it. Keep notes about what you are doing and relate that to your results. That will help you nail the focusing/exposure very quickly.
Vandit - would love to learn more about the stock image sales. Do you do any images u/w for stock purposes?
To be honest, I dont have any of my UW images in stock - my file simply isnt large enough (and after a HD crash earlier this year where I lose 3 months worth of images, it is even smaller) and so I am not marketing what photos I have, except as a bundle with magazine articles. I'd rather lose some sales now, rather than have a potential buyer contact me and be unable to meet his requests.
In my neck of the woods, there are probably 2-3 people doing underwater photography, so getting it placed wont be a problem, I think. Given the ever-declining returns from my land-based stock images, especially in this market, I am not too fussed about even placing it - the only reason I'd do so would be for some exposure to the buyer's market.
Placing with a Getty or Corbis would be more financially profitable, but as UW photography is rarely location-specific, you will need a really outstanding set of images or a very large collection of species portraits to get in with one of the big boys. And shooting expressly for stock sales is the surest way to kill one's interest in photography & creativity, IMO.
If you are just looking for some side money, Alamy or a similar newer agency would be a good bet. They went through a phase of indiscriminate portfolio-adding (esp in Nature/Wildlife/Landscape) but seemed to have tightened up now, or so I am told. They could be a good bet.
Vandit