Years ago when I was a beginning scuba diver, I was baffled by all these cylindrical objects laying about on the ocean floor. I even asked a fellow diver and he didn't know. I had no idea where they came from or what they were UNTIL, one day I was photographing this FUGLY sea cucumber and I found out what those cylindrical objects were! Note to self - if you laugh at yourself underwater, you WILL flood your mask. UH...should this be mature content?? I'm thinking immature content.