Just so everyone understands what happens in the BVI and other Caribbean islands regarding the swell. The North swell actually has nothing to do with wind. You can have a massive North Swell with dead calm winds. You will always have waves or what I call wind driven chop that form with the wind and move in the same direction. It’s usually short period waves which can make for an uncomfortable ride out on the water especially bashing into the wind. Swell on the other hand starts in the North Atlantic often off the NE US during nor’easters. That is why it’s predominantly a winter issue. Those storms create long period swells in the ocean that take a few days to move down to the BVI. This is why they can be accurately forecast. Out on the water they don’t cause any real issues. Just a gentle up and down motion on the boat and they are rounded and smooth unlike wind blown waves that are short and steep turn into whitecaps at about 15 knots.
Swells becomes an issue however when they reach shallow water. They carry large amounts of energy and when the hit shallows turn into breaking waves. This is why North facing anchorages can become nasty in a swell. The amount of water moving can also wrap around islands and impact anchorages not north facing if it’s a large swell. They can even reflect off one island back to another. You can see these effects in White Bay JVD in the winter. Sometimes in the winter you get my personal favorite. Christmas winds out of the east with a North swell. Now you can have 4 to 6 foot seas in 20 knots of wind crossing the swell at 90 degrees. Makes for a long week. Here are videos of North swell in CGB. Note there is no real wind.

https://www.youtube.com/watch?v=ZRXHUCc8t4o

https://www.facebook.com/BritishVirginIs/videos/2657169884335209/