# SCUBA question **URL:** \ **Category:** Factual Questions\ **Created:** [June 26, 2000, 2:04am UTC](https://boards.straightdope.com/t/scuba-question/23517 "2000-06-26T02:04:50Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![onelittlebug](https://avatars.discourse-cdn.com/v4/letter/o/dc4da7/32.png) [@onelittlebug](https://boards.straightdope.com/u/onelittlebug)\ **Post date:** [June 26, 2000, 2:04am UTC](https://boards.straightdope.com/t/scuba-question/23517/1 "2000-06-26T02:04:50Z")
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. ---
**Author:** ![Johnny\_L.A](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johnny_l.a/32/1084_2.png) [@Johnny\_L.A](https://boards.straightdope.com/u/Johnny_L.A)\ **Post date:** [June 26, 2000, 2:21am UTC](https://boards.straightdope.com/t/scuba-question/23517/2 "2000-06-26T02:21:57Z")
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. ---
**Author:** ![divemaster](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/divemaster/32/78_2.png) [@divemaster](https://boards.straightdope.com/u/divemaster)\ **Post date:** [June 26, 2000, 3:12am UTC](https://boards.straightdope.com/t/scuba-question/23517/3 "2000-06-26T03:12:50Z")
Where were you diving? There’s a good probability you were hearing snapping shrimp. ---
**Author:** ![GusNSpot](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gusnspot/32/436_2.png) [@GusNSpot](https://boards.straightdope.com/u/GusNSpot)\ **Post date:** [June 26, 2000, 3:16am UTC](https://boards.straightdope.com/t/scuba-question/23517/4 "2000-06-26T03:16:58Z")
da diveman got it. also can hear something similar in a pool in town but is not really the smae, crawdads are not shrimp. 😛 ---
**Author:** ![KCB615](https://avatars.discourse-cdn.com/v4/letter/k/ea666f/32.png) [@KCB615](https://boards.straightdope.com/u/KCB615)\ **Post date:** [June 26, 2000, 3:34am UTC](https://boards.straightdope.com/t/scuba-question/23517/5 "2000-06-26T03:34:51Z")
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? ---
**Author:** ![Sofa\_King](https://avatars.discourse-cdn.com/v4/letter/s/58956e/32.png) [@Sofa\_King](https://boards.straightdope.com/u/Sofa_King)\ **Post date:** [June 26, 2000, 6:25am UTC](https://boards.straightdope.com/t/scuba-question/23517/6 "2000-06-26T06:25:07Z")
I’ve clearly heard the sound of parrotfish scraping rocks with their teeth while feeding. It makes a very discernable “cracking” noise. ---
**Author:** ![onelittlebug](https://avatars.discourse-cdn.com/v4/letter/o/dc4da7/32.png) [@onelittlebug](https://boards.straightdope.com/u/onelittlebug)\ **Post date:** [June 26, 2000, 1:59pm UTC](https://boards.straightdope.com/t/scuba-question/23517/7 "2000-06-26T13:59:20Z")
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. ---
**Author:** ![handy](https://avatars.discourse-cdn.com/v4/letter/h/b5a626/32.png) [@handy](https://boards.straightdope.com/u/handy)\ **Post date:** [June 26, 2000, 3:30pm UTC](https://boards.straightdope.com/t/scuba-question/23517/8 "2000-06-26T15:30:08Z")
I hear it in planes. ---
**Author:** ![mipsman](https://avatars.discourse-cdn.com/v4/letter/m/e99b99/32.png) [@mipsman](https://boards.straightdope.com/u/mipsman)\ **Post date:** [June 26, 2000, 4:43pm UTC](https://boards.straightdope.com/t/scuba-question/23517/9 "2000-06-26T16:43:36Z")
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.