Mayor
Contributor
Mayor agree with all the above advice and by all means try it without an external strobe first you may be pleasantly surprised. I am a long time UW Sony user and a voice in the wilderness on this. They do have their disadvantages (older ones were shifted green UW) but the newer ones seem to be much better but not perfect.
Far and away their biggest advantage is the size. I use a P150 and it is tiny, topside it fits in a pants pocket, UW in a BCD pocket for getting in and out and under a strap while UW.
My rules for the Sony are simple get close, use the flash. If you break either rule you will be disappointed. For massive amounts of examples go to my web page (below) and look at some of the newer shots, all of those were with a Sonp DSC-P150 internal flash. The earlier ones were with a DSC-P10.
Cecil & Sue's Home Page
The pictures look great. Glad to see someone else using a Sony.