Singing Hulls

My old Hobie (pictured here in 1975) would make this very erie singing sound when the boat was on a certain tack at a certain speed. The hulls would resonate. On one occasion, it attracted dolphins who came up alongside the boat, they swam directly under me while I was hiking out. Very cool. That was well over 30 years ago. Do the newer Hobies still make this sound? Has anyone else experienced this phenomenon?

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Karl, Captain of Stayin' Thirsty
2011 Hobie 16SE
Atlanta, GA
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What you remember is "rudder hum" caused by cavitation of the rudder trailing edge. Racers eliminate the noise by filing the trailing edge sharp, others just think it's cool.

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Damon Linkous
1992 Hobie 18
Memphis, TN

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fixing ventilation, aka 'rudder hum'

http://www.hobiecat.com/support/articles/archive/?src=http://2010.archive.hobiecat.com/support/tech/hum.html
I like thoes sails on your '75 Hobie.

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Gray Amick
Chapin, SC
'77 NACRA 5.2
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