Island_Moose 0 Posted October 9, 2014 Share Posted October 9, 2014 I've been living on my Nonsuch 30 for a reasonable period of time now (there are several country-music songs that discuss why). I had the opportunity to sleep in a "land-bed" while travelling on business the other day and couldn't get to sleep. Why? I missed my crackling friends...the NZ snapping shrimp that keep me company at night (pop, crackle, snap, snap, pop). They are sure doing well on my hull (haul out in November) and the dock next to me. I was told that their "snap" has been recorded at 218 dB....seems high. Link to post Share on other sites
wheels 543 Posted October 10, 2014 Share Posted October 10, 2014 218dB? Unless measured right at the actual claw....maybe. A Sperm Whale can make a Sonar Click at...(I think it was)... 188dB and that is a loud enough to actually render a diver unconscious if he was in front of the Whale. However, if that is the little Pistol Shrimp that stuns it's prey with a snap of it's fing...I mean Claw, it is indeed a powerful snap and apparently the shock wave is caused by the cavitation of the water, which can produce 6000deg heat and a flash of light. Apparently. Never seen it myself. You'd think the water would be little flashes of light all over the place at night. Link to post Share on other sites
Rhys 0 Posted October 13, 2014 Share Posted October 13, 2014 The reason that the level appears so loud is that noise is described as a change in pressure against a reference pressure. The reference pressure in air is different to that of water, hence different levels. It’s also related to the speed of sound in the medium. The energy is the cavitation bubble is truly prenominal. It’s currently one of the holy grails of acoustics as several groups are working on ways of harnessing the resulting energy. It could potentially outperform nuclear energy, all from a glass of water. Link to post Share on other sites
Old Girl 0 Posted October 14, 2014 Share Posted October 14, 2014 All to high tec for me. But they drive me nuts, I need to spend more nights on board it seems. Actually just now they will silenced by they hull growth I should think. Link to post Share on other sites
John B 106 Posted October 14, 2014 Share Posted October 14, 2014 I don't mind em , I still laugh though when I think of the wags in the cruising races who'd tell all the newbies , us included, that the noise was ( drumroll)....... Electrolysis ooooooooooo. Link to post Share on other sites
waikiore 397 Posted October 15, 2014 Share Posted October 15, 2014 Us timber boat users have nothing to fear from the crackling of ' Osmosis' slowly working its way into your fibreglass production boat. That's always my favourite to tell them. Link to post Share on other sites
John B 106 Posted October 15, 2014 Share Posted October 15, 2014 Hah, what about the polyestermites! Those things'll eat yer glass boat in no time. Link to post Share on other sites
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