I am retired US Navy and was stationed at Guantanamo Bay for 3 years as a Medical Deep Sea Diving Technician. As such, I had plent of opportunity to dive most all of the bay. I can't say I've ever seen a UFO/USO, but I do believe in the poosibility of other world alien life.
Diving in Gtmo was generally good, with water depth as deep as 50-60 feet in the areas around the ship channels and it's doesn't seem to have a lot of debris other than a few wrecked/crashed WWII aicraft.
If you go off shore aprox. 1 mile, you hit a drop off that goes to almost 600 feet. Visibility is generally good except when a storm rolled in, then the water was cloudy and turbid.
My time stationed there was 1986 to 1990 and was of the few professional, military-trained divers. Our responsibility was all work done on ships from he waterline and below, and we managed to stay busy.
I wish I could offer you info regarding UFO's, but I can't claim to have ever seen any.
I hope my scant info will help with any questions about local conditions for divers. The has always been a large dive club there and they dive constantly.
Thanks for your time.
Ray Gwaltney, HM1/DV (Ret)