saved this fisherman. He knew the trap lines ran east to west and drifted with the current to the end to pick up a buoy. The CG search and rescue pattens did not help in this situation. Coincidentally I been doing some dead reckoning at home navigation practicing back to a MOB --as an exercise and have come up with a simple idea that chart plotter manufacturers should build into their units. I've written to my manufacture Coastal Explorer but haven't heard back from them. This is the idea. When the MOB button is activated rather than just dropping a way-point and activating a bearing back to that waypoint, that the computer generate an expanding square starting at the MOB with each leg no more than one mile from the adjacent leg. A route so to speak. This is a recommended search pattern.
Under my idea, if the MOB is not at the waypoint when the vessel get there the auto pilot would go into the search pattern, as if it was following the route, freeing the captain to do a visual search and guaranteeing a comprehensive search. This is a very simple thing to program into existing software that can do routing already. It could save a life.