Big swells are not a major problem if the period is rather long. You are just "driving over the hills and dales" sort of thing. What is a problem is if the swells meet an shallow underwater shelf. Then they will "pile up" and make rather large impressive short period waves or even breakers.
- - Staying in deep water
keeps you out of that problem - but when you find a harbor to anchor/moor in - look at the shape of the harbor and determine the direction the swells will enter the harbor. Swells wrap around islands so an ocean swell from the north can end up being a west (or east) swell on the backside of an island.
- - If there is a point or cape that the swells must "wrap around" then the best place to anchor
to avoid the swells in in the "shadow" of that point/cape.
- - If no choice is present and other boats are not a factor you can deploy a stern anchor
to pull the bow around so it faces into the swells. Pitching up and down is a lot easier to take than rolling gunwale to gunwale.
- - There is also a version of a bridle
if you are using nylon rode
on your anchor or even on a mooring
. You run a second line off the stern of the boat
to the anchor rode/mooring line and pull the stern around to try to get the bow into the swell. This works well when the wind
and swells are 90 degrees from each other. Of course in heavy/strong winds this is not advisable as you are presenting a large wind
face to the maybe dislodge the anchor or overload the mooring
- - IF all that doesn't work
you then sleep in the main salon
on the floor where the motion is least - or spend most of your time ashore.