Steelyeyes
Contributor
Dropping rec. divers in 500ft of water beside a shelf at 30ft sounds unnecessarally risky. Just saying ...
Happens quite often in the Caymans. The wall at Cayman Brac is 5000 (thousand, not typo) feet to the bottom. Bloody Bay wall on Little Cayman is 1000 feet to the bottom. Buoy anchors are on the edge of the wall and depending on wind and current the aft end of the boat is over the abyss almost every morning wall dive.
As mentioned above the divers enter the water, swim to the buoy, descend on or near the buoy line and generally meet at the anchor, at least until the DM's assess your skill set.