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.