Cathy Church
Registered
Several DSLRs have time lapse settings. A tripod helps a lot. Ultralight makes a terrific one with a "foot" on the bottom of each leg that look like a half a whiffle ball. Finding the right subjects is the hard part. You want it to look amazing like starting with a group of conch in the sand and watching them run away in the time lapse. Have a diver swim in, stop and swim off to the side. Sometimes just behavior is good enough if a cleaning station or a school of fish is moderately active. You will enjoy experimenting with things in your dive area. Practice your settings above water, then walk in and out of the scene and see what speed of walking produces the feel you want.