skin

When a sail is furled, the fabric that remains visible on the outside, covering all the layers beneath it, is called the skin. On a square sail furled to the yard, the skin is the portion of canvas you see from deck level, wrapped around the bundled folds of the rest of the sail. It serves a protective function, shielding the inner layers from weather, UV damage, and chafe against the yard or spar.

The skin takes the brunt of environmental exposure during storage aloft. Salt spray, rain, and sun attack this outermost fabric, which is why it often shows discoloration or deterioration before the protected layers underneath. On well-maintained vessels, the skin may be treated with preservatives or coated to extend its life, though a worn skin does not necessarily mean the sail beneath is compromised.

Practical considerations

The condition of the skin affects how easily a sail can be loosed when needed. A skin that has become stiff, cracked, or partially fused to the yard by salt or mold creates friction during unfurling and can delay sail handling in urgent conditions. Sailors learn to work the skin carefully when furling, ensuring it lies smooth and even so it sheds water properly rather than collecting it in pockets.

On modern synthetic sails, the skin may be a different weave or even a different material than the body of the sail, chosen specifically for weather resistance. Traditional canvas skins on cotton sails absorbed water and required careful drying after bad weather to prevent rot. The term skin persists even on roller-furling jibs and modern fore-and-aft sails, though the principle is identical: the outer visible layer that takes the environmental load.