Storm Sails

Why Storm Sails Exist

Reefing reduces your working sails to a point — typically two or three reef positions in the main, and roller-furling or a smaller headsail forward. Beyond that point, the remaining sail area is still too large, the centre of effort is too high, and the sail shape is distorted. Storm sails are purpose-built for conditions beyond the working sail range.

Storm sails are not just small sails. They are built from heavier cloth (typically 8–10 oz Dacron), with reinforced corners, triple-stitched seams, and oversized grommets and attachments. They are designed to survive the loads of 45–60 knot winds and to set a clean, flat shape with no draft — draft in survival conditions produces heel, which is the opposite of what you want.

The two storm sails: A storm jib (or storm staysail) is a small, flat headsail, typically 5–8% of the boat's total sail area. A trysail is a small, flat mainsail that sets on a separate track (or on the mainsail track) without using the boom. Together, they provide enough drive to maintain steerage while keeping the boat's heel and windage to a minimum.

Most cruising boats carry storm sails but never rig them in practice. This means the first time the crew attempts to fly a trysail is in 45 knots of wind and 5-meter seas — exactly the wrong time to learn. Rig your storm sails in moderate conditions at least once per season.

The Storm Jib

The storm jib is a small, flat headsail set on the forestay (or an inner forestay/removable staysail stay). It provides forward drive and helps the boat maintain steerage in survival conditions. The key characteristics are:

Size: 5–8% of the boat's I × J (foretriangle) area. On a 12m boat, this is typically 4–6 square meters — tiny compared to a working genoa. World Sailing/ISAF regulations specify maximum storm jib area based on boat measurements.

Cloth weight: Heavy Dacron (8–10 oz) or storm-weight polyester. The sail must survive sustained loads in 50+ knots without deforming or tearing. Lightweight racing cloth will shred.

Attachment: Storm jibs should be hanked on — using piston hanks or snap shackles on the forestay. Roller-furled storm jibs exist but are controversial: if the furler jams in heavy weather (a common failure), you have a half-furled sail that's both too large and impossible to furl or drop. A separate hanked-on storm jib, stowed in its own bag near the forepeak, is the reliable choice.

Sheeting: The storm jib sheets to the working sheet tracks or to dedicated storm jib sheet blocks positioned further inboard. The lead angle should be flat — a storm jib should not have twist at the leech. Sheets should be oversized (larger diameter than working sheets) for grip and strength.

If you have a cutter rig (inner forestay and outer forestay), the storm jib sets on the inner forestay. This is one of the significant advantages of a cutter for offshore work — the storm jib goes up on the inner stay without touching the roller-furled genoa.

The Trysail

The trysail replaces the mainsail in storm conditions. It is a small, flat, loose-footed sail that sets on the mast track (or a dedicated trysail track) and sheets to blocks on the deck or quarter — not to the boom. The boom is lashed amidships and plays no role.

Why not the boom? In survival conditions, the boom is a lethal pendulum. A trysail sheeted to the boom would require the boom to be controlled — vang, preventer, mainsheet — all under extreme loads. By eliminating the boom from the storm sail plan, the trysail simplifies the rig and removes the most dangerous moving part on deck.

Sizing: 10–15% of the mainsail area. On a 12m boat, this is typically 6–10 square meters.

Track options: Some boats have a dedicated trysail track on the mast, separate from the mainsail track. This is ideal — the mainsail can be lowered and secured on the boom while the trysail slides up its own track without interference. If no dedicated track exists, the trysail uses the main track — but the mainsail slides must be removed from the track first (a difficult job in heavy weather).

Sheeting: The trysail clew sheets to blocks on the quarter, typically at the chainplate area or stern quarter. Two sheets (port and starboard) allow the trysail to be trimmed for either tack without jibing the sheet. The sheets run outside the shrouds and lifelines.

When to switch from reefed main to trysail: When the second reef is no longer sufficient — the boat is still overpowered, the helm is unmanageable, and conditions are still building. In practice, this is usually above 35–40 knots of sustained wind, depending on the boat.