Sail Tips

SAILS FOR OFFSHORE SAILING

Weight, strength and durability mark the essential ingredients in well-made offshore cruising sails

by Brian Hancock

SO, YOU HAVE DECIDED TO GO BLUE-

water sailing. That itch finally has to be scratched. It’s time to get your boat ready. There is a lot to do especially when it comes to your sail inventory. The sails that you used for harbor hopping around the bay on weekends will probably not cut it when far from land when a sudden squall rolls through at two in the morning. With that in mind, let’s take look at sail engineering for offshore sails.

First of all, it’s going to cost some money but that investment in fabric and engineering up front pays huge dividends down the road. It really is a case of you get what you pay for. You need to have three goals in mind; weight, strength and stretch resistance, and durability.

Weight is important, especially weight aloft. Unnecessary weight aloft adds to the heeling and pitching motion of the boat, which over time contributes to crew fatigue. Think of sailing to windward with a sack of potatoes tied to the masthead. It can’t be good. Lighter sails are much easier to handle and much easier to set and trim. They also don’t take up as much space below when stowed.

utmost importance. Even though you are cruising and time is not really a factor, show me one sailor that does not try and eek out a little extra performance from his boat and he or she will be the first one I have ever met. Even cruisers want performance, and you can get that by choosing not only the correct fabric, but also the correct engineering.

Let’s take a Dacron sail for example. The high load in a sail is up the leech and along the foot. In the body and luff area the loads are greatly diminished, however the sail designer has to engineer the sail for the leech and foot loads meaning that there is a lot of overkill in the rest of the sail. The workaround is this. A light base fabric throughout the sail with a second ply added in the high load areas. It’s takes more labor and uses more fabric, but the result is a much better engineered sail.

Laminates are different. They are generally used to build radial sails, and this panel configuration allows the sail designer to place a heavier fabric up the leech and along the foot and a lighter fabric in the body of the sail. Membranes are an entirely different subject and we will get to them.

Durability is key for any sailor heading on a long offshore passage. While it’s possible to repair sails at sea, it’s not easy and probably not something that you want to be doing. There are a few things to consider. Chafe is your enemy and there is plenty of chafe on any offshore passage especially when the sails are eased. Start by adding spreader patches. On the mainsail add spreader patches not only where the main rubs against the spreaders at full hoist, but also where it rubs when the sail is reefed. On your headsail there may be chafe where the foot of the sail rubs against the lifeline when the sail is eased out. You will also need to add spreader patches to all overlapping headsails. Sail your boat on all points of sail and note (or mark if you can) where the fabric is rubbing up against some part of the rigging. If you use stickyback Dacron (applied to a clean, dry

sail) you won’t have to sew it down.

In terms of engineering, extra large corner reinforcement patches are a must. They distribute the immediate corner load out into the body of the sail. There will be times when you have sails up in winds in excess of their designed wind range, that’s just part of sailing offshore where the wind can change without warning. Large reinforcement patches will go a long way toward preserving the fabric and by extension, the shape of the sail. Consider adding a second leech and foot tape. They really do give the sail that extra grunt that you need especially when you need it. An overhead leechline on the main is a worthwhile investment. A fluttering leech can very quickly ruin the fabric but without an overhead leechline it’s a challenge to tighten the leechline to stop the flutter. An overhead leechline allows you to adjust it at the tack of the sail at the relative security of the mast.

We can’t leave this subject without taking a look at membranes. What once used to be the sole purview of the racing sailor, is now becoming increasingly common among cruisers. The cost of membrane sails has come down and the performance and durability has gone up. The way that a membrane sail is engineered is so precise that the strength and stretch resistance far exceeds that of even the best laminates.

The individual yarns are laid precisely along the anticipated load paths for the greatest efficiency. The individual yarns can be different using the more high tech (read more expensive) yarns in the high load areas and a less expensive, less exotic yarn in the body of the sail. This helps keep the cost of the sail down. These yarns can be encapsulated between different types of taffetas to add overall durability.

Membrane sails hit all the buttons for good offshore sails. They are light and easy to set and trim, their strength and stretch resistance is off the charts, the taffetas can be rugged and if you combine these factors with plenty of chafe resistance you will end up with great sails for an offshore voyage.

Remember, you need to measure the life of a sail by how long it holds its shape, and not just by how long it simply holds together. With all of this considered you need to make the best decision based upon your budget and long term sailing goals. And one last thing to consider. Try and keep your sail plan as simple as possible. Work with your sailmaker to come up with an inventory and layout that allows you to change gears easily as the wind fluctuates.

BWS

Brian Hancock is a veteran offshore sailor and racer and is the principal sail designer at Great Circle Sailing. He is based in Marblehead, MA.