When things get hairy at sea, you need to be able to reduce sail to suit.

Most cruising boats have two or three sets of reef points in the main, but once the wind’s up to Force 7 or above (35 knots plus) even that is likely to be too much sail.

Mostly, and especially with today’s excellent weather forecasting, we don’t venture out in that much wind: but sometimes, should a harbour or anchorage become untenable, should the unexpected happen and a storm hit at sea (or, simply, should we want to go for a windy sail), it pays to be prepared.

Ocean sailors can make their trips much more comfortable with suitable ways to reduce sail.

As with any debate in sailing, the decision over whether to use a trysail or an extra reef in the main is founded in decades of opinions.

The case for the trysail

A trysail is an odd beast to look at, but has a cutaway tack and a long foot which, instead of using the boom, sheets to the toerail.

The cutaway tack allows waves to pass underneath the sail, causing a minimum of damage to sail and spars.

The leech and foot are both hollowed to avoid the edges flogging in heavy winds.

But the main advantage of a trysail is that it avoids the need for the boom.

Booms are dangerous things at the best of times, but swinging around in a gale, they can make moving around hazardous.

With the trysail up, the boom can be lashed to the deck, keeping it (and you) safely out of harm’s way.

Downwind, this is especially important.

As the boat rolls, the boom can hit the water, leading to damage and, potentially, a broken boom.

But with the boom lashed down and a trysail set, things become much more manageable.

Using a trysail also means you can protect your mainsail for longer instead of flogging it as you try to sail in extreme conditions.

Trysails can also be used in conjunction with a sea anchor to keep the boat’s bow to the wind.

The case for adding an extra reef

Some people prefer to add a fourth reef to their mainsail instead of using a trysail.

This, they argue, is not only safer, but much easier to set up.

Instead of battling sailcloth (many trysails require you to remove most of the sliders from the mast, then flake and lash up the mainsail), they argue that you can simply slab in another reef, which is quicker, safer and easier than battling a trysail.

There’s also a performance advantage, the same people will claim, over a trysail – a deep reefed mainsail is likely to let the boat point better upwind.

Tips for using a trysail

Practise with it on a moderate day so you can know its workings inside out.

Write instructions for its specific use on the outside of the sail bag.

If you’re planning some ocean or high-latitude sailing, consider adding a separate track to the mast.

This allows you to leave the mainsail attached via its sliders and to simply hoist the trysail on a separate track. A hi-tech system is made by Harken.

Similar to a railway line, the trysail is attached to a separate track which merges with the main track at a set of points above the deck.

You can leave both set up and simply switch between the two.

The system is available in 26, 32 and 50mm sizes.

Getting a trysail made

International Offshore racing rules state that the area of a trysail should not exceed 17.5% of the mainsail luff length x mainsail foot length.

This means that, as the leech and foot are hollowed out, the area will be roughly 25 to 30 per cent of the mainsail.

Offshore racing boats are now required to have the sail made from high-visibility orange cloth, or at least with a large orange patch on the sail – this aids visibility to other craft in big seas.

How to set a trysail, step-by-step

It’s a great help if you can know what to do with the trysail before you need it – here you can see written-on instructions for hoist height, downhaul tension and sheet positions.

1. On this boat, the first job is to lower and secure the mainsail.

2. The top 10 sliders must be removed from the mast track.

3. That done, the stack pack can be zipped up. We added a few extra sail ties to the sail and boom to keep it secured.

4. The lazyjacks must be taken forward and hooked around the reefing horns.

5. This done, the boom can be lowered and lashed to the toerail – here, we’re using a length of Dyneema for extra strength. The mainsheet can then be tensioned to keep the boom secure.

6. Boom secured, we can rig the trysail. Starting from the bottom, the sliders can be inserted into the mast track.

7. The main halyard is attached, and some tension is taken on it to stop the halyard from winding round the spreaders: a problem that can be surprisingly difficult to rectify in 40 knots of wind!

8. The downhaul line is fed through an eye and tied off so that the tack will be level with the exit for the spinnaker pole uphaul. This ensures that the clew is at the correct height.

9. The sheets are now rigged through special blocks, which are located as far aft as possible. You’ll need two separate sheets – many people use their mooring lines. On many boats, the spinnaker sheet blocks are ideal for this, being well positioned.

10. With the sliders inserted, the trysail can now be hoisted and sheeted home. It’s best if you can keep some tension in the sheets from the start to avoid the clew flogging in the cockpit.

11. With the trysail hoisted, you can adjust the luff tension with the main halyard as you would a normal mainsail to improve the shape as required.

Sailing with a trysail

Sailing upwind

Because there is no boom, the trysail sheets must be taken to the quarters – but this means that pointing is sacrificed.

While in most storm situations you’re unlikely to need to make ground to weather, instead riding it out, there are occasions where you may need to go upwind.

With the leeward sheet tight, you can pull on the windward sheet to act as a traveller and pull the clew to windward, if height is required.

This lowered our speed somewhat, but the pointing angle was much improved.

Some recommend using a reefing pennant taken from the end of the boom to use as a sheet, whereupon you can use the trysail much like a heavily-reefed mainsail.

This will improve your pointing ability as you can use the traveller and mainsheet as usual but isn’t as safe if you’re simply riding out some rough stuff.

Sailing downwind

Sailing downwind in waves is where the trysail really comes into its own as it does away with the boom.

However, to stop the sail’s clew flogging around as you approach dead downwind, it’s helpful to add another sheet, this time with a more vertical pull.

We’ve used a snatch block attached to the rail to pull the clew downwards and keep the sail under control.

The danger of gybing is also lessened – the sail can begin to try and gybe, but the new sheet stops it from happening.

A rig consisting of a trysail, clew pulled down, and a jib poled out is a very safe way of sailing downwind in lots of wind and big waves.

Sailing on a reach

Sailing on a reach, the trysail has few differences from a reefed-down mainsail.

Unaffected by the issues which stop you pointing upwind, and by the rolling issues downwind, it provides ample power with some protection against large waves washing over at deck level.

Storm jibs

As with a trysail, many people never look at their storm jibs, and most cruising sailors are unlikely to need theirs.

Different types of storm jib

Boats with roller-furling headsails often have a problem when it comes to wanting to hoist a storm jib – that of having to lower their furling sail first, which is no mean feat on a wet, pitching deck.

But why not simply furl the normal jib?

There are a few problems with this.

Firstly, the shape won’t be as good, and a partially-rolled sail will have more windage.

If you’re going to make any ground to windward in a storm, you’ll need the best chance, which means a separate storm jib.

A rolled jib will be baggy and full, which will simply result in more heeling and more leeway, less windward movement and more discomfort for the crew.

A proper storm jib will also be made from much heavier cloth, making it far more suitable for a windy day.

Some options are available that allow you to hoist a storm jib on a rolled-up forestay.

But perhaps the best route is to install an inner forestay.

This will allow you to use a separate working jib in clement weather (always better from a performance point of view than a rolled jib) and fly a storm jib in heavy weather.

Best of all, it moves the centre of effort back to match that of the mainsail, which will have moved forward when reefing – or when changing to a trysail.

This will improve the boat’s motion and make her much easier to handle.

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