tips for canon s300/ixus 300

hello...i just tried my s300 underwater last weekend...the shots i took weren't that great but i think the prob is with me coz i was worrying about lotsa things and it was my first time to take photos underwater so for any here who has used this type of setup could u give me some tips that i might use on the next dive...for one thing i think the flash isnt that great so i have to move really close to the subject. i havent tried lighting the subject with dive lights which i might consider on the next dive..anyhow any tips would be greatly appreciated..thanks very much