This is a second hand report from a retired military fighter pilot. I'm not sure if you'd want to post this but I thought you might be interested in at least reading about it. If you are interested in learning more, you can contact me and I could also contact the pilot directly and see if he'd be interested in talking to you.
I was talking to a Vietnam veteran who flew F-4 Phantoms off of a carrier in the Vietnam war.
One evening he was assigned to a carrier defense flight to ensure no enemy aircraft got close to the carrier group. When flying past the carrier, it was suddenly lit from below the water by a very bright light.
He was commanded to circle and observe the light. The initial theory was that a Soviet sub was under the carrier and was somehow shining a light up at them, playing games with them. After about a minute though, the light took off through the water still submerged.
They and another jet followed above for about 20 seconds when the light left the water, not sure if they saw the shape, and took off straight up into the air and vanished.
When back on board the carrier, all personnel were commanded to never mention the incident.