SCUBA question

I went SCUBA diving for the first time in the ocean this weekend. At about 50 feet, I started to become conscious of a “cracking” sound. It resembled the sound that ice makes in a lake when a large crack shoots through it, except constant. As I began to surface, the sound became less noticible. Could this noise be my skull compressing under the pressure or is it just the ambient noise of the ocean.

I haven’t been diving in years (I decided flying was a lot less like work!). I doubt the sound you heard was your skull compressing. I seem to remember a “crackling” sound too, from time to time. I’ve also heard the sound after swimming. I put it down to water and/or air bubbles in my ears.

So I’m not much help. But it’d be interesting to find out what it is.

Where were you diving?

There’s a good probability you were hearing snapping shrimp.

da diveman got it. also can hear something similar in a pool in town but is not really the smae, crawdads are not shrimp. :stuck_out_tongue:

Only cracking sound I’ve heard is my ears equalizing, but that normally goes away once I’m done. Swallowing can cause a cracking sound, too, but again, you’d probably make that connection. Like divemaster asked, where were you diving?

I’ve clearly heard the sound of parrotfish scraping rocks with their teeth while feeding. It makes a very discernable “cracking” noise.

I was diving off of West Palm Beach at Breakers, Flower Garden and Bath and Tennis Reefs. I don’t think that the noise was coming from inside my ears. I had no problem clearing them, and the sound wasn’t muffled at all. I did see quite a few parrot fish feeding so I guess it could have been them.

I hear it in planes.

I spent last week sleeping in a thinned hull boat in the Bahamas where I heard the clicking sound. The dive experts identified it as snapping shrimp. I’ve heard the same sound while trying to sleep off Catalina Island. I was beginning to think the snapping shrimp were nocturnal.