Crackling Sound Below the Waterline on Steel Boat

[Icarus]

Originally Posted by KelseyB

So. I have noticed that there is a crackling sound coming from outside my boat below the waterline and I am very curious as to what it is. Sounds like Rice Krispies—I really don't have any other descriptors for it.



I have a 30-foot steel boat, and I am very nervous about electrolysis because she's in an industrial city with (probably) a lot of stray currents running around. She has plenty of zincs, but it's always a fear. I read some other posts saying it's shrimp and other marine life feeding on the bottom, but my boat was launched exactly 1 week ago with a fresh bottom job. The first time I launched the boat with a fresh bottom job, I don't remember hearing any crackling sounds. I first heard them 8 months after that first launch, when there was some algae on the bottom and the boat was in Florida at the time, so I didn't have any issue dismissing it to marine life. But now, with a fresh bottom job and at a dock in a river that isn't particularly "teeming with life," I am a bit suspicious. Anyone have any idea what the sound could be? Should I be worried?

Plankton, steel amplifies sound...all good

[Mare Nostrum]

Your link is absolutely fascinating & so complete...many thanks for sharing!!

[Stomp]

I had my Fibreglas Beneteau 45 in Nanny Quay in the BVI’s last year and had many a worried session lying face down with my head under the floorboards worrying about the rice crIspies!!!! ; ))
Thankfully by the time we set off for Bermuda we had eaten them all and we had a much quieter time on the water !!!
Once we arrived in Europe the waters were quiet and I soon forgot about The whole experience.