Waterproof Case Housing

Waterproof Case Housing
2 questions about Canon cameras. (For diving)?

I look forward to buying the Canon G9 and use it for scuba diving (underwater.) I get the WP-DC21 Waterproof Case, but I want to be able to get a strobe light. Is it possible to attach a flash to this while in the box? Besides, what would best to get the 650 instead? I read a site saying "External flash: No" .. I was not sure whether this meant that they are unable to connect a flash or not .. I am a big noobie enough to the cameras, so please any suggestions would be great! Here is the link for the G9 housing, if useful. Http: / / www.amazon.com/gp/product/B000V74S1Y/ref=cm_rdp_product Thanks!

Quote from BHphotovideo.com in the wp-DC21:>>> You can use the camera's internal flash for lighting your. Or, use flash internal trigger an external slave flash, as made by Fantasea, Sea & Sea, Ikelite, Sealife or Sunpak. The camera has a white balance setting for photography underwater light available. <<<The 650 is an excellent camera, but the G9 is a camera more capable than the 650. It has more features like the ability to mount an external flash unit. If you can afford it, I'd go for the G9.

Scary Underwater Ice Fishing Footage from Dark House