When we`d go for a dive , we`d have a shore marshall with details of number of pax on board, an emergency vehicle clearly marked and parked un obstructed. 2 local doctors numbers and addresses, a helicopter landing site scoped, chamber numbers and route to nearest chamber and we`d let the local coastguard radio where we were going, how long we`d be there and when we`d be back. That was just for a recreational dive. Plan the dive and dive the plan .