Before GPS, it was much harder to find the carrier in the wide ocean. Pilots relied on a combination of inertial navigation, radio communications and good old-fashioned maps. Capt. Jim Lovell — best known as the commander of the ill-fated Apollo 13 space mission — tells a story about returning from a 1954 mission in his McDonnell F2H Banshee night fighter. Due to an electrical failure, Lovell’s instruments went dark in the cockpit. In the middle of the ocean at night with the cockpit lights out he noticed a glimmer of photo luminescent algae that had been stirred up by carrier USS Shangri-La. He followed the trail home and landed safely.