As an Instructor I would allow my students to bring a camera on dive 4 only, provided they aced dives 1-3. Not a case of playing god, simply keeping the task loading to a minimum for someone new to diving. I have a DC310 and can say that it is a decent camera all around but it has been discontinued for a intents and purposes.
The DC 500 is out with a few diffent options as far the package you select or you may want to take advantage of the Olypmus and its' current $50 dollar rebate.
http://www.diversdirect.com/scripts...?Template=9990000041000999&searchinput=dc+500
http://www.diversdirect.com/item/Olympus SP-350 Digital Camera_ID43263
http://www.diversdirect.com/item/Olympus PT-030 Underwater Housing for SP-350_ID43262
The DC 500 is out with a few diffent options as far the package you select or you may want to take advantage of the Olypmus and its' current $50 dollar rebate.
http://www.diversdirect.com/scripts...?Template=9990000041000999&searchinput=dc+500
http://www.diversdirect.com/item/Olympus SP-350 Digital Camera_ID43263
http://www.diversdirect.com/item/Olympus PT-030 Underwater Housing for SP-350_ID43262