Meteorologist Chris Tibbs offers some pointers on downwind sailing...

What is the best set-up for downwind tradewind sailing? Different ideas abound, but there is really no right or wrong way, because what may be good for one boat and crew might not necessarily work for another. Conditions change from year to year, experience and crew numbers vary and what may be right for a family or short-handed boat won’t suit a fully crewed yacht of racing fanatics.

Some crews will tell you that the autopilot will steer all the way; others will mostly hand steer. Some yachts are much more fun to steer while others are heavy and not very responsive. There are many ways to do the ARC. Here are some points I have picked up over the years.

Watch out for chafe

Some things are the same on all boats and one enemy of downwind sailing is chafe. From halyards exiting the mast to sheets and guys, a long time on one gybe can cause havoc to ropes and leads. It is worthwhile checking ahead of time where these chafe points are likely to be – preventing it is much easier than dragging a spinnaker out of the water at 0200.

It is a good idea to go round the deck and check for chafe or loose fittings every few hours. Although halyards can’t be checked on this basis, on racing boats they should be moved every watch. This changes the wear point and lengthens the life of the rope. It is also kinder to the rope to leave halyards on a winch rather than a jammer.

Spinnaker or not?

Little in the sail wardrobe causes more argument than the spinnaker – whether or not to have one and when to fly it. On a long downwind crossing, it is a shame to restrict yourself in the ability to sail quickly, however, a spinnaker will only help if you have the crew numbers and ability (along with deck fittings) to fly one.

Parasailor

Poled out headsail

Without a spinnaker, most crews will use a poled-out headsail, unless they have some type of specialist sail. With the main out one side and the headsail poled out the other, you get an easily controlled and seemingly efficient rig.

Twin headsails

Twin headsails have their fans as well as detractors. This varies from purpose-built headsails that may be linked (eg Twistleyard or Tizzlerig) to a cruising chute or second genoa, either on a second pole sheeted to the rail or through a snatch block on the end of the main boom. With a twin-headed rig, the main can be up or down and will be flexible on the angles.

Angles are very important. There is a section of the sailing fraternity that will put up twin headsails and point at the mark, be it downwind or a reach. Others will sail the angles, happy that the increase in speed more than makes up for the extra distance sailed. How much you need to head up before the extra distance more than compensates for the extra speed is not an argument I want to get into here.

Sail with a vent

There are several specialist downwind sails you can use for a tradewinds crossing of the Atlantic. One that comes up often and looks a little strange is the Parasailor. It is a spinnaker with a vent and is said to be better mannered than a traditional version and can be set with or without a pole.
With the vent, it will tend to allow the wind to blow through, so gusts will have less of an effect and it will provide added stability. You’ll need a snuffer on the sail, but this is a good idea for any long-distance cruising with a spinnaker. Not only can a sail be tamed quickly but, once down, it goes straight into a bag without the need for woolling or rubber bands. Snuffers, like all new gear, need a bit of practise to avoid twists, but with a bit of care in stowing and hoisting, they can be avoided.

Steering or self-steering?

There are other considerations. Autopilots and wind-driven self-steering gear do not like running downwind, as the waves knock the boat off course. Twin headsails are perhaps more forgiving because there is no danger of gybing the main, but I would rather head up, hand-steer and have fun.

But uncontrolled gybes are not fun. Most crews will lead a preventer from the end of the boom to the bow and back to the cockpit. This does not need to be a high-tech rope, as something with a bit of stretch will absorb some loads if you do accidentally gybe. To set it up, it is good to make it in two parts: a length that lives permanently along the boom and a second piece of line that attaches to this that goes to the bow and back to the cockpit. This makes setting it up and gybing easy, as you don’t have to get to the end of the boom to tie it on, nor do you have excess amounts of rope hanging from the boom during the gybe.

Squall tactics

Squalls will always cause excitement but, as a rule of thumb, will most likely be windy if the clouds are raining. Plus, the higher the clouds, the stronger the initial gust front. Non-raining clouds will give some gusts near their edge, but are unlikely to create any real wind, whereas big, raining squalls can give a gust front of gale-force wind quickly dropping.

I am not a fan of roller-reefing mainsails and a well set up slab-reefing system can be just as quick and have all lines leading to the cockpit. Any reefing downwind is punishing for a sail, as it is dragged against the shrouds. Shape and a larger sail area of a more traditional main win over a roller mainsail, but there are times when being able to roll the sail away at the end of the day is nice – perhaps not a good argument for a transatlantic!

Choosing your sails

There are various degrees of high-tech sailcloth and specialist sails. When choosing sailcloth for long-distance cruising, look for types that are easy to repair and can withstand a certain amount of abuse. I like fully battened mainsails, but the ease with which you can reef them, particularly downwind, and chafe on the rigging are considerations.

Many cruising sailors stick to Dacron because it is a good all-round cloth that is reasonably forgiving. Even when it has lost its shape, it does not delaminate and is still usable. It can be repaired by any loft in the world or any heavy-duty sewing machine.