Unidentified fish?eel?

Unidentified fish?eel?

Observation - Unidentified fish?eel? - Global. Description: We were snorkelling approx 30 m off the beach in around 10 to 15 feet of water when I spotted something gliding thru the hole in the attached picture that was like a window onto a tunnel (thru which the animal was gliding). At first I thought it was a fis

We were snorkelling approx 30 m off the beach in around 10 to 15 feet of water when I spotted something gliding thru the hole you can see in the attached picture. The hole was like a window onto a tunnel thru which an animal was gliding. At first I thought it was a fish, but it seemed like it took a couple of seconds to pass the 'window' and was therefore longer than I would expect a fish to be. I couldnt see how wide its body was. The skin was patterned but I dont recollect what the pattern was particularly, other than it seemed like dark patches (stripes?) on a much lighter back ground (I may have that the wrong way round!). I saw it go twice past the 'window' and took a photo but all I got was what you now see - just the tail.