What's that cracking niose coming from beneath my hull?

[paul]

What\'s that cracking niose coming from beneath my hull?

For some time now I've heard a noise which sounds like a fire crackling or rice crispies popping under my hull. As I don't seem to have a fire nor do I have any rice crispies on board it must be something else. Any ideas?

thanks

Paul

 

[WindFinder]

Re: What\'s that cracking niose coming from beneath my hull?

[ QUOTE ]
For some time now I've heard a noise which sounds like a fire crackling or rice crispies popping under my hull. As I don't seem to have a fire nor do I have any rice crispies on board it must be something else. Any ideas?

[/ QUOTE ]

Nothing relevant to offer but I recently read a book on the Mary Celeste and the one theory on what happened (in fact there was far moe evidence for what happened than I ever realized - suspect the evidence was omitted from accounts to make it seem more interesting and mysterious) is that the swelling timber cargo (packed frozen IIRC) cracked and sounded just like a fire burning. Indeed it wouldn't have been the only ship to be abandoned for exactly that reason.

I appreciate this is of no help at all but it's kind of relevant to your post and I've typed it out now so I'm hitting the button anyway!

 

[david_bagshaw]

Re: What\'s that cracking niose coming from beneath my hull?

Prawns or other marine life feeding?

 

[machurley22]

Re: What\'s that cracking niose coming from beneath my hull?

Snapping shrimp perhaps?

 

[cliff]

Re: What\'s that cracking niose coming from beneath my hull?

Sounds like Polymites in a feeding frenzy just before their breeding cycle. Best have your boat lifted and treated for polymites as if left untreated these little creatures can and will chew their way through FRP. They particularily like polyester based GRP but are also known to chew epoxy. You should also tell the owners of the boats moored around you that you are infected so they can have their boats treated as well and in the meantime fly flag "D" to warn other boats to stay clear. /forums/images/graemlins/ooo.gif /forums/images/graemlins/wink.gif /forums/images/graemlins/grin.gif
---------------------

Artificial Intelligence is no match for Natural Stupidity

 

[thurloo]

Re: What\'s that cracking niose coming from beneath my hull?

hi when did you last clean it ??? if you got shells and normal growth on bottom its the little crechers moveing round and feeding, but not on your structure, it is normal , if you need cleaning then thats what it is dave

 

[jimbaerselman]

Re: What\'s that cracking niose coming from beneath my hull?

Agreed, snapping shrimps. There was considerable research on this subject by the US Navy during the cold war, because the background noise created interfered with sonar detection.

 

[jimmynoboat]

Re: What\'s that cracking niose coming from beneath my hull?

Had the same thing on a SunSail boat in Greece years ago. We had no idea what it was and even wondered if it was some kind of leak.
SS imediately said 'It's fish feeding off the hull'
You wouldn't think they'd like rice crispies would you?

 

[VicS]

Re: What\'s that cracking niose coming from beneath my hull?

[ QUOTE ]
snapping shrimps. ................... during the cold war,

[/ QUOTE ] Just hope its not buster crabs!

 

[bilbobaggins]

Re: What\'s that cracking niose coming from beneath my hull?

"The old 'uns are the best 'uns....?"

Clearly a fan of the Sainted Des!

/forums/images/graemlins/grin.gif

 

[PuffTheMagicDragon]

Re: What\'s that cracking niose coming from beneath my hull?

Fish grazing on the bottom growth. Scared the 'stuff' out of me when I first heard it during the first night that I slept on board an old Vivacity that I had. My ear was only a couple of inches away. First reaction was "Gribble!" before I remembered that it was a GRP hull. /forums/images/graemlins/blush.gif

 

[NealB]

Re: What\'s that cracking niose coming from beneath my hull?

[Clearly a fan of the Sainted Des!

/forums/images/graemlins/grin.gif

[/ QUOTE ]

I'm going to both show my age, and reveal a horrible streak of pedantry, but, credit where credit's due: I think it was the late, great Bill Beavis (rather than the late, great Des Sleightholme) who dreamed up the polyestermite in 'Looking around' as a YM April fool too many decades ago.

 

[Bejasus]

Re: What\'s that cracking niose coming from beneath my hull?

dunno how many times I have posted this now, but it will indeed be snapping shrimp

 

[dunedin]

Re: What\'s that cracking niose coming from beneath my hull?

Interesting. We heard a similar sound on a charter boat in the Hauraki Gulf. Was a bit disconcerting at first, sounded like some form of electrical fault, but came from underneath.

 

[cliffordpope]

Re: What\'s that cracking niose coming from beneath my hull?

It's the pack ice tightening its grip. Best load stores onto the sledges and prepare for a long haul.

 

[oldharry]

Re: What\'s that cracking niose coming from beneath my hull?

Its the dreaded Osmosis bubbles forming in the gel coat, and cracking into the GRP.

First heard it 50 years ago in my old Lysander..... /forums/images/graemlins/laugh.gif

 

[mawm]

Re: What\'s that cracking niose coming from beneath my hull?

I agree with Cliff - Polymites. If left untreated they will sink your boat. They are not hard to get rid of, but you do need a special polymite spray to apply to your boat. This can be done easily by you while your boat is safely moored.

5 Gal will cost only $100 - that is enough to do your average 32 footer. I can be contacted at

underwaterspray@Ship'o'fools.com

 

[sighmoon]

Re: What\'s that cracking niose coming from beneath my hull?

We had the same thing on a charter boat in Greece. I thought it sounded like soap bubbles popping. Charter co said it was barnacles dying off because of the antifouling.

Personaly though, I've decided it was sand drifting past in the current. I heard something similar much later while snorkeling - and I'm sure it was sand that time because I saw lots of it.

 

[Sailfree]

Re: What\'s that cracking niose coming from beneath my hull?

[ QUOTE ]
I've decided it was sand drifting past in the current.

[/ QUOTE ]

Is there much of a current in Greece?

 

[sighmoon]

Re: What\'s that cracking niose coming from beneath my hull?

No, there isn't. The snorkeling was somewhere else, but it sounded much the same.

We only heard the sound at night, so I wonder if there's a bit of a convection fed current, as surface water cools, and the water that was at the bottom rises, bringing sand with it.

Of course I really don't know, but I think that sounds convincing.