Heya. Can anyone tell me what the crackling noise is i can hear through the fibre glass??
Unless it's marine dwelling drop bears. They are not fussy about what they eat. Best not to go on deck for a while.
Select to expand quoteSectorsteve said..
Heya. Can anyone tell me what the crackling noise is i can hear through the fibre glass??
I get this as well. its a soft bubbling crackling sound from under the water. same as yours?
Don't worry it's just the osmosis or electrolysis trying its hardest to join your party!
It's actually the strands of fibreglass breaking. When enough of them snap, the whole boat vanishes into a cloud of old resin.
Well, that's what used to worry me when I was a kid, before we sailed over some shallow reefs and I realised it was crustaceans. On the same note, years ago we were in the Whitsundays and you could hear the waves calling when you were snorkelling. Great stuff!
Waves... whales I think. 
Cracklings OK but when you start to hear crunching....... 
That's the Bream chomping away telling you its time to haul out and redo your anti-fouling!! 
I just wish the bream would eat the growth right down to the hull, so we wouldn't have to anti foul at all.
i get the same sounds , no idea what it is but its a wonder of the world , just add it to one of the lists of wonders !!
I get it too and have theorised it's the small wavelets 'slapping' the hull - but I don't think it holds water 
regards,
allan
"Snapping shrimps" is the correct term. It's just the crustaceans going about there business as stated above. Very noticeable if your tied up to a wharf. Remember that sound travels further and much faster underwater.
I'm sure it's crustaceans etc, because when you sail over a shallow reef in light winds you can hear the sounds increase.
From the net;
"Crustaceans make noise for defensive and, possibly, courtship purposes, but the unknowns far outweigh the data. A variety of crabs, lobsters, shrimps and other crustaceans have developed noise-making capabilities as diverse as those employed by terrestrial insects.
The crackling made by barnacles as they open and close and move their articulated appendages can be detected for miles. The predominant sound coming from coral reefs is the incredibly loud popping of tiny bubbles (cavitation) generated by hordes of small snapping shrimp for hunting and communication. Mussels can produce sound by stretching and breaking the byssal threads that attach them to the substrate. Urchins have been observed making crackling noises by clicking their sharp spines as they move. This crackling can also be caused by the urchin's test (the shell surrounding its body cavity) rubbing against its Aristotle's lantern (feeding apparatus)."
One tiny shrimp is one of the noisiest animals around;
"Divers have witnessed the ceaseless cacophony that colonies of these shrimps produce; their loud crackling sound has been described as if a hundred people are cracking their knuckles at once, or like sizzling of fat in a pan or like 100 people bursting bubble wrap at once!"
www.todayifoundout.com/index.php/2010/09/a-shrimp-is-one-of-the-loudest-animals-on-the-planet/
I had the impression it was the tiny baitfish nibbling barnacles etc on the hull.
It would great to have a definitive answer!
All very interesting, however I do like Chris 249's rendition of the fibreglass strands breaking.
Crikey, my boats 30 years old. When is the cloud of old resin going to happen???.
I was always told it was phosphoresce (you know the stuff that glows in the water when you swish water around at night) ???
Early in my naval career I was a sonar operator, mid sixties. It's snapping shrimps.
According to that link in the post above, shrimps are the loudest animals on the planet!
Select to expand quoteSectorsteve said..
Heya. Can anyone tell me what the crackling noise is i can hear through the fibre glass??
Yes. It is a particular kind of marine worm that thrives on fibreglass.
The Universities have captured a few of them and in test tanks with a fibreglass rich environment have attempted to analyse thier digestive system and how it assimilates glass. They have not yet come up with an answer of how but do acknowledge that it is a very real danger to owners of fibreglass yachts.
If you are on your yacht of an evening, having a quiet drink and can hear the sound of those worms crackling away, chewing the bottom out of your pride and joy, you need to get a new mooring spot as soon as possible before the water level in your yacht gets higher than the grog level in your throat.
That is a very real danger.
Select to expand quoteSectorsteve said..
According to that link in the post above, shrimps are the loudest animals on the planet!
NO AC DC are Sector Steve Ill tell you next month after there concert 
Select to expand quoteHG02 said..Sectorsteve said..
According to that link in the post above, shrimps are the loudest animals on the planet!
NO AC DC are Sector Steve Ill tell you next month after there concert
I went here in Sydney. Was bloody great---
