Trysail

Controlling Weather Helm while on a Run

Weather helm is a phenomenon where the force on the sails wants to turn the yacht up and into the wind. This is caused by having the Center of Effort (CE) of a sail aft of the Center of Lateral Resistance (CLR) of the underwater profile. Balancing the sails is simply the act of playing around with the CE to get it to be directly in line with the CLR.

If the CE is ahead of the CLR, the boat will have lee helm and will want to turn downwind. If the CE is aft of the CLR, the boat will have weather helm and will want to turn upwind. Only when the CE and CLR are directly over each other will the sailboat be balanced and sail straight, not venturing upwind or downwind.

Balancing the sails is not the same as trimming the sails for maximum performance. A lot of time, you will need to have your sail working at less than peak performance to properly balance out the whole setup. This is easy when you are sailing on a beam reach, where all the forces acting on the yacht are coming from the side, but what about on a run?

To be on a run, you need to ease your mainsail all the way out so that it can act as a large drag to the apparent wind and be pulled along, likewise pulling your yacht along with it. Here is where it gets tricky.

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As you ease your sail out, the CE of the sail will not only move forward, which will help give you lee helm and pull your yacht downwind, but it will also move the CE laterally and outboard. This long and very powerful lever arm, also known as your boom, will act on the mast and try to turn your yacht opposite of the direction you have eased the sail. In this case, with the boom eased to port, the force on the sail will try to turn the yacht to starboard. This may feel and act like weather helm, but it is not caused by the aft movement of the CE, instead it is caused by the leverage of the mainsail held out by the boom.

The further outboard the clew of the sail is, the longer the lever arm is that is acting on the yacht, and more leverage the sail will have to turn the yacht in the opposite direction. 

Your options here are simple, either you can move the clew further in or not ease the sail as far. Moving the clew inboard is effective at reducing this torquing. This can be achieved by either reefing the sail or simply not easing the clew past the beam of the boat. Obviously, these options seem counterintuitive as the apparent wind while on a run is less than the true wind; more sail would seem logical!

Instead of reefing, and dealing with the boom on a run, an alternative is to raise the trysail. 

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The trysail has no boom, so the foot will curl more easily when the sail is eased. As you ease the sail, the clew will tend to move directly forward from the sheeting point, and as such will stay inboard of the beam of the yacht. 

The sail is also smaller but when eased will fill up and provide a great amount of drive downwind. Since the sail will curl up, the majority of the sail will be right along the mast, in the middle of the rig, further keeping the CE close to the midline of the yacht. 

Being a small sail, it also won’t block the wind from reaching your headsail. This will increase the headsails effectiveness which will then aid in keeping the bow of the ship pointed downwind.  

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Having a trysail up on a wonderful day may not seem intuitive, but it really does help take out the weather helm while sailing downwind. This will balance your sailplan and let your yacht sail more balanced towards your downwind destination.

Dedicated Trysail Track

A trysail is a small storm sail that is flown in place of your mainsail. It usually lives deep in a sail locker stuffed into a bag. Here it typically remains for the entire life of your yacht.

The idea behind a trysail is that should the winds pick up to severe speeds, you can drop your mainsail and raise the trysail. This takes all the stress off your mainsail and puts it solely on a dedicated and purpose built sail.

The problem in this narrative is that the sail is stuffed away where it is forgotten, and therefore, seldom used. In a storm, the last thing you want to do is root through a locker, pull out a sail, remove the mainsail, attach it to the luff, and then raise it. When a storm hits, you want to make your main smaller and get back to the cockpit as quickly as you can!

Having a dedicated track for the trysail allows you to set it up before you leave port so that should the situation arise, it is ready to go.

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We flake and then ball up our trysail at the foot of the mast, where it remains laying in wait for the moment we might need it. We have the starboard sheet tied to the clew, so all we need to do is attach the port sheet once the mainsail has been lowered; and its dedicated halyard already attached.

When we need the sail in a hurry, we just drop the main and raise the trysail. The starboard sheet is set, so worst case scenario where we don’t have time to attach the port sheet before raising, we can sail on port tack. The clew of the trysail is low enough that I can easily reach it to tie on the port sheet after it has been raised without reaching overboard or far off the deck (I’m tall though).

With the trysail setup like this, we find that we use it very often, which makes our blue water passages very relaxing and safe, since we can don the storm sails just as easily as we could raise our working sails.

Nighttime Sailplan for Innexperienced Crew

When you have new crew on board, you are never certain about their abilities and judgement. Some will talk a big talk to make you think that they know what they are doing, but these kinds are all talk; and totally clueless at the helm. 

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There is a huge difference between "knowing how to make a sailboat move" and "knowing how to sail". When you have new crew who can move a sailboat and will talk it up a whole bunch, you will want to try them out and see what they really know before putting them in charge of a watch cycle on their own. 

Some of the issues that will come up during nighttime watches is the need to reef, and the ability to hold a course. Sure, when you are inland, you can sail all you want until the weather turns and just drop the sails at that point. In the ocean, it is not that simple and storms can produce much more powerful waves out at sea. 

High winds and tall waves will make it harder to put in a reef, especially in the dark on a moonless night. To avoid this problem it is prudent to reef down at sunset so that if something comes up unexpectedly, you are already reefed and ready for it. 

Reefing is great because it makes the mainsail smaller, but it still involves the boom. If you have inattentive crew at the helm, they might not notice that they have veered from course and about to jibe until the boom comes crashing over. Repeated powerful jibes can damage and destroy your traveler as well as damage the metal of your spars. It is best not to do this! 

To avoid this problem, at night, we simply fly the trysail. It is small, our smallest sail and sail of choice for powerful storms; so we couldn't possibly reef down any further. It also negates the use of the boom. This means that if your new crew, or tired crew is not paying attention, a jibe is merely the flopping of a tiny sail with little load on it to the other side. No loud crashing or stress on your gear involved. 

Running with No Boom

Downwind sailing is always easy, the wind and waves are at your back, the apparent wind feels lighter, and you can go directly towards your destination. The only headache in the system is the mainsail's boom. 

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One trick we have found to get around the booming issue is to not use the boom at all! When sailing on a dead run, we will set the headsails and the trysail. This gives us a few advantages. 

First, there is no boom to worry about with accidental jibes. 

Second, there is less weather helm since you have a small sail flying.  

The combination of the two means that you can point downwind towards your destination and not worry about a thing. If you jibe, the trysail will flop over as effortlessly and un-dramatically as the headsails.