During my first FYN Naked Spring Bash, the gang from Vita Nuda Northeast brought the sealed ball that you see in the second half of the video and they used it at the pool in Sunsport.... I was not about to get in that thing, though :P
You are SEALED in there and it is possible to run out of oxygen O_O... just sayin.
Also, can you imagine losing someone in the sealed ball in the ocean? Nuh-uh, never getting in that thing!