Ever see the film of the old Tacoma Narrows bridge? Same thing. Potentially
damaging? You decide. I'd do some rig tuning, but my methods are a bit
unorthodox and difficult to explain. The effect you are trying to achieve is
to break the ability for the rig to achieve harmonic resonance aka Mast
Pumping in your case.
"MLapla4120" wrote in message
...
Hi,
I have a sailboat and when it gets windy at the slip, sometimes there is
a vibration and the mast and rigging seems to resonate and vibrate.
Someone
told me this is 'mast pumping'. I was also on another sailboat visiting
and it
did it also. Nobody seemed concerned.
My question is; should I be concerned? We get regular wind here at
twenty
knots and sometimes more. The pumping seems to last about 3-5 seconds.
Then, it stops and resumes a little later.

Thanks for any info.