Underwater quality factors

just wanting to know what to look for in a camera, so that i can be sure that it will perform nicely underwater in low light conditions.

the camera that i am looking at currently is the SONY MINIDV HANDYCAM DCRHC21

thanks for any help in advance

The most important thing you have to check before buying a camera for u/w use is that the model you want have an u/w housing.

Check in reviews sites like dpreview AF performance in low light, usually in the in-depth reviews they checks this issue.