Bring mask & snorkel, a 7mm wetsuit with hood, a weight belt and weights, a lanyard, and long freediving fins, preferable 100% carbon fiber like these
ones. Because of the strong currents, you should not swim out to this spot with scuba or snorkelling fins. Because of the low visibility, you should not dive at this spot without a lanyard.
If you are in charge of the buoy, make sure you have a tall dive flag for visibility, preferable with lights. A VHF radio with which to call the Coast Guard on channel 16 in case of emergency is recommended.