Black sponge?

[dagrath]

While diving Point Lobos last week, my buddy and I spotted something we hadn't seen before. It was a very dark black, round, about the size and shape of a Harley Davidson motorcycle helmet. The half helmet type.

Right on the top of was a red "eye". We jokingly called it the Eye of Sauron when we got back to shore. We couldn't find it googling, and really have no idea what it was.

Anybody seen one of these, and have any more details?

 

[dwashbur]

Sounds like a Giant Keyhole Limpet, Megthura crenulata. They're notoriously difficult to get a good picture of, and this one has a lot of backscatter, but did it look something like this?

 

[dagrath]

Sounds like a Giant Keyhole Limpet, Megthura crenulata. They're notoriously difficult to get a good picture of, and this one has a lot of backscatter, but did it look something like this?

That would be it! Awesome, thanks.

Unfortunately, we didn't bring a camera with us.

 

[dwashbur]

Glad to help. Two things never to dive without: your buddy, and your camera!

Here's a better picture of the limpet: