When sailing downwind, you might find that the main is stealing all of the wind form your jib. This will manifest itself as a jib that continually falls and can never remain full of air. This loss of sail area will translate into reduced speed through the water, which means it will take you longer to get to where you are going.
There are a few ways to rectify this situation:
- You could broad reach instead of run
- You could lower the main
- You could reef the main
- You could raise the topping lift
- You could sail wing on wing
Broad reaching will put your yacht at an angle to the wind, allowing clean air to reach your headsail and fill it. This will cause your yacht to sail faster, but it will also add additional distance to your destination. It is pretty much the equivalent of tacking downwind. If you do some math, you can find an angle where your Velocity Made Good is higher than if you were sailing on a run, making the extra work worthwhile.
As stated, broad reaching would be more work than running. In the effort of keeping effort to a minimum, lets look at how we can run more efficiently. The headsail offers significant sail area, but it is hidden behind the mainsail. If wind could get around the main, the headsail would also fill, letting you sail faster while still on a run.
You could lower the main, allowing all of that wind to reach the headsail. This will move you along with a full headsail, but you are still suffering from lost sail area. If your headsail is massive, this might function better than the main, giving you a bit more speed, but there are other options.
If you reef the main, it will be smaller and wind can get around the top of it and past the leech, letting this wind reach the headsail. The fuller headsail will provide more power when combined with the main and will help pull you downwind at a faster pace.
Instead of lowering the top of your sail, you could always raise the bottom. Tightening the topping lift will raise your boom and let air scoot by under the main to reach the foot of the headsail. Sailing along with a twisted main and headsail will be better than sailing along with a main and fallen headsail, but there is still a better way.
Instead of trying to get the air around the main, why not place the headsail in its own clean wind? This is called sailing wing on wing.
When on a dead run, as in the wind is directly behind you, you can set the main on one side of the yacht and the headsail on the other side. Each sail can be set full and in its own clean air with no disturbances or compromises. Now you have all your sail area functioning to carry you straight downwind towards your destination with as little effort as possible.
You must be wondering why more people don't like to set the sails in these manners? Well, to sum it up:
- Broad reading is more work than running
- Dropping your main and sailing under headsail alone is usually as fast as sailing under main alone
- Reefing the main is work, and when people are running, they don't want to work
- Raising the topping lift will induce twist into the main and cause it to chafe on the rigging
- Wing on wing is very prone to accidental jibes.
Accidental jibes are a real and present danger when sailing wing on wing. A preventer can be used to stop the main from slamming across the boat, but preventers can make a mess if you need to change directions quickly, so I prefer to not use one. Instead of using a preventer, I will sail along at a slight angle to the wind, so I am not truly on a dead run, but instead the slightest of broad reaches.
With the main set on the leeward side, this slight angle will protect against those accidental jibes. If I see that my angle to the wind is changing, I can correct it before the boom comes smashing across the cockpit. With the main set to leeward, the drifter will be set to windward.
The drifter is a very safe sail to fly by the lee, as it is simply a nylon genoa with a very full cut. It will stay on the windward side and fill up like a kite. If I sail too far off angle the drifter will fall and lay against the rigging. There is no noise, bashing, or terror on board when this happens. I just alter course a little bit to fill the drifter with wind and continue on our way.
Sailing at a slight angle won't guarantee that accidental jibes won't happen, they just reduce the likelihood. Since they are still a very real and present issue, I don't recommend sailing wing on wing in strong winds. If I can't grab the mainsheet as it runs out to the boom and pull the whole boom towards me without any assistance, I won't sail wing on wing. If it were blowing harder, the pressure on the main were greater, I would not be able to pull the sail as easily and there would be more potential for damage if an accidental jibe did occur.
Another issue with wing on wing sailing in strong winds is you are at higher risk of broaching. The sails are set on either side of the hull and the rolling waves could push the boat into a roll which could lead to a broach or worse, a Chinese jibe! Keeping this sailing technique restricted to light air days will ensure that running is as little work as possible, letting you reach your downwind destination in comfort and with ease.