I was in the US Navy for about 10 years, and have 10s of thousands of miles at sea in an aircraft carrier. Countless nights on the flight deck in the middle of the night and middle of the ocean...
Creepiest: A HUGE patch of the ocean glowing. Like nuclear waste in the Simpsons glowing. I've seen bioluminescent algae of a few kinds and this was nothing like it. I've never seen anything like it before or since.
Weirdest thing: hundreds of mile out to sea from land and there was a MASSIVE fire on the water. It was like the top of a gas refinery, but on the water with nothing under it but water. Flame going a few stories into the air.
Saddest: a fellow sailor trying to jump overboard. He apparently got a 'Dear John' email and pictures from his cheating wife and decided to end it. We were on the smoke deck, he bummed a cigarette, then asked the time, we said 2300... he replied "sounds like a good time to die" and in one motion tried to launch over the chest high wall (with an opening to the water below). Luckily we were faster than him. We grabbed his legs and wrestled him down and laid on him and basically hog tied him till the MAs (Navy cops) got there. Broke my heart because he was a good dude. I never saw him again. He got transferred off the ship shortly after. Not sure what happened to him but I hope he's doing better.
Funniest: 2 flying fish collide mid-air. I was smoking when we were in the Persian Gulf and saw the fish fly from a pretty far distance towards each other. I remember thinking 'there's no f****n way they're going to hit' them SPLAT SPLASH! I was in tears laughing but no one saw it. Everyone just thought I was a weirdo, but I got to see a miracle of nature lol