text: One is that sea-faring people believed that pilot fish , which would appear around the bow of their ships when they were close to land , were leading ( or piloting ) them back to port . An alternative etymology is that pilot fish were once , erroneously , thought to be piloting sharks to food , or even ( as legends have it ) piloting ships , whales and swimmers to safety .
simplified: It could be because sailors people believed that pilot fish were leading ( piloting ) them back to port , or even leading swimmers and whales to safety .