Helicopters
After World War II, amphibious aircraft were experimented with for plane guard duties and search-and-rescue roles. However, prior to the Korean War, helicopters were discovered to be more efficient and effective in both roles. As helicopters came into more common usage, they supplemented and sometimes replaced plane guard ships, as they could retrieve crashed aircrew faster and safer than the ships. However, night operations required a ship in the plane guard position.
Read more about this topic: Plane Guard