I've only done a few night dives! They're fun, but creepy. Being underwater is already kind of scary and intimidating, but when you're field of vision is reduced to the tiny, directional beam of your torch, it's even more scary. Here's a pufferfish I found and swam with for a while.
Puffer fish! I swam with this guy for a while. He didn't seem to mind me so I used the flash on my camera (which helped bring out some of the reds and oranges that weren't showing up on the camera using available light).