Just wondering if anyone knows if I would need to purchase a strobe for this camera or will the flash on the camera do the job.

An external stobe would give better results.

Bev, what model do you have? A DSC-T1 or DSC-P150 or DSC-P200. It does matter I have heard the T1 has a weaker flash while the P150 and P200 have a better flash.

Almost all UW photographers will always say get an external flash. I am the exception, I don't like the bulk or the expense. I have been using a Sony DSC-P5 for the last three years w/o an external and do pretty well. Here's a link to some pictures taken recently in Bonaire.

The two things an external gets you are a little more range and off axis lighting. The latter will greatly reduce backscatter. I find the internal has plenty of range for the stuff I shoot, I do like to get close which is the best choice anyway. I also find backscatter to not be a big issue if you get close and try not to shoot up into the water column.

YMMV.

Cecil
Great pictures I would be happy with those results.
My camera is a Sony W7, with 7 mega pixels. It does have a option of changing the flash to be stronger.