Downwind Sails and Rolling

[Joli]

As others have said, gybe down wind. You need to bring some pressure to the side of the sail plan to steady it and stop it from rolling. You get the benefit of breeze across the deck, stability, and speed.

[roverhi]

Without a pole, a headsail will collapse and fill constantly if you are sailing lower than about 140 degrees to the relative wind. It's unnerving and hard on the sails and rig to have the jib constantly collapsing and filling. Really fun with an Asymetric Spinnaker as the sail will sound like a cannon, with equivalent load on the rigging, when it fills.

Just finished a Transpac with 11 days of running wing and wing on my Pearson 35. Averaged better than 6knots on the Rhumbline to Hilo with winds from 10-15k. Reaching off would have been way slower in progress to our destination and probably only netted us about a 1/2 knot through the water because we'd have had to sail so far off the rhumbline course to keep the headsails filled. You can sail at least 20 degrees and probably 30-40 degrees off the DDW relative wind running Wing and Wing. A longer than 'J' pole or an adjustable whisker pole is really a benefit for reaching up running W&W.

We sailed about 170 degrees to the relative wind and sailed about as flat, with virtually no rolling, as it's possible in the 8' +/-seas. The self steering did yeoman work as the wind vane oscillated from lock to lock to keep the boat on course. Sailing slightly off the DDW course may have been the reason for the flat sailing. I didn't have the vanged main fully out because of chafe on the aft lower. The boom was about 45 degrees off the centerline.

On my old Westsail 32, ran with headsails poled out without much rolling. The W32 is reputed to be a roller but ours didn't roll much at all on that long DDW run. We had a reacher drifter poled to one side and the yankee jib lead to the main boom on the other. Perhaps the grossly different square footage of the two sails cut down on the rolling moment.

[Hydra]

When selecting the course for downwind sailing in a seaway, consider the directions of the waves and the swell. It is very common to have primary and secondary swell coming from directions very different from the waves.

If one perturbation (waves or swell) has an average "encounter period" (resulting from Doppler effect) close to the natural roll period of your boat, it will cause rolling. To avoid this, there are 2 choices:
- change the course or the speed sufficiently to alter the encounter period
- catch that perturbation exactly on the longitudinal axis (head waves or following waves).

Then, it is worth experimenting and changing course by as much as 45deg to find the best one. I remember an occasion when there was a slight swell and the wind was coming in puffs. Between puffs, I had to alter course by more than 30deg and take the swell precisely on the bow to prevent the sails from flapping on each crest.

If your boat is a non-planing one and already at "hull speed" dead downwind, gybing downwind will not increase the speed by much.

Alain

[Pete7]

Originally Posted by rdempsey

I like this idea:

The Twizzle Rig or Twistle Rig for Downwind Ocean Sailing

Dave, Swagman on here was the owner who has done some long cruises with the Twizzle rig. Haven't tried it, but I like the idea of being able to quickly roll away two Genoas to reef.

Do a search on twizzle

http://www.cruisersforum.com/forums/...rig-29360.html

[DannySt]

If you are going with a geni and a main, what worked for me a couple of times is to loosen a bit the boomvang, or the main halyard, and tighten the leech line.
This will give the main a bit of a balloon shape and will hold the wind better.

[stevemac00]

I find wing-on-wing fastest if I have enough wind to keep sails full. I use a Dutchman Boom Brake to give a little more forgiveness.

But many times I've tacked downwind. Sailing 20 degrees off to one side of the rhumb line only adds 6% to distance covered. If boat speed goes up 6% you'll obviously arrive at about the same time. So if you can increase your speed from 5 to 5.3, you can arrive at the same time more comfortable.

Above numbers take from vigor's handbook.

[rebel heart]

Sailing on a broad reach is a lot more comfortable and forgiving than being on a dead run anyway.