Most of what you get as far as waves are wind driven. Generally out of the East in the BVI. Wind driven waves are generally short duration and peaky making for a poor boat ride going into the wind.
The North swell common in the winter is a long duration deep wave that originates off the Eastern US. The swells roll all the way down to Caribbean. They are very comfortable to sail in even when large as they provide a nice smooth motion. They become a problem when they hit shallow water and become steeper faced or even breaking waves. Because they are moving large amounts of water they can work their way around and into anchorages that don't even face North.
You can have a north swell on a otherwise perfectly calm day. You can also have a strong east wind that will produce the wind chop 90 degrees to the swell.
Since the swell originates far away the forecasting is very accurate. It's almost down to the hour when they will begin and end . There is no reason to be surprised. I often change my itinerary based on the swell forecast. You don't want to be overnighting in CDB or White Bay with a swell predicted.
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Last edited by GeorgeC1; 10/25/2015 01:58 AM.