Foul weather gear and layering.

Inshore, coastal and offshore

Foul weather gear is sold in grades. The magazine Trade-a-Boat explains the difference: offshore gear is built for harder use, with heavier fabric, more features and a higher overall standard, while coastal gear is lighter, protects less and suits the tropics. Practical Sailor's 2003 jacket test (updated online in 2019) adds that coastal jackets are lighter, easier to move in and come in more styles than offshore jackets.

Trade-a-Boat lists features you typically find on offshore gear:

• Welded seams
• Latex seals at the neck or wrists
• Attachment points for a lifejacket
• Reinforcement at wear points
• Hoods with stiff visors

It also says top-tier offshore gear uses three-layer fabrics and lighter ranges use two-layer constructions. Some brands use their own rating scales; Gill, for example, says its three-dot rating marks gear for coastal and offshore use with high breathability and durability (Gill's own description, as quoted by Practical Sailor).

Waterproof and breathable

Two figures come up when jackets are compared. The first is hydrostatic head, a waterproofing rating given in millimetres. Motor Boat & Yachting (MBY) treats about 10,000 mm as coastal grade and 20,000 mm or more as offshore grade. That is one magazine's rule of thumb; we could not confirm it as an industry standard. In MBY's 2026 roundup, makers rated their offshore jackets between 20,000 and 30,000 mm, but those are the manufacturers' figures, and MBY did not test them.

The second is MVTR (moisture vapour transmission rate), a breathability figure. MBY advises looking for a high figure to avoid a plastic-bag effect but gives no target, and we found no independent laboratory breathability figures for sailing jackets.

How a breathable membrane works

Trade-a-Boat describes GORE-TEX as the first breathable fabric used in this kind of gear. The following figures are Gore's own claims, which Practical Sailor also labels as Gore's: the membrane is expanded PTFE about 0.01 mm thick, discovered by Bob Gore in 1969, with about nine billion pores per square inch. Each pore is said to be far smaller than a water droplet but far larger than a water vapour molecule, so rain stays out and sweat vapour gets through. Gore markets the fabric as Guaranteed to Keep You Dry and says it tests the products other brands make with its membrane. It also sells newer products built on an ePE membrane.

What older tests found

Practical Sailor's independent tests are useful but dated, so treat their findings as history rather than a current ranking.

• Jackets, 2003 (updated online 2019). Practical Sailor found little difference in waterproofing or breathability among the jackets it tested, and brand-name microporous alternatives to Gore-Tex performed about as well as Gore-Tex.
• Full suits, 2008 (updated 2020). Testers found the better garments came closer to being truly windproof and waterproof, while the others were only water-resistant. The differences showed up in hood and collar design, wrist closures (some Velcro cuffs wore out after 200 cycles), seat and knee patches, reflective material and zippers large enough to use with gloves.

The general lessons still apply when you compare gear today: look at the hood, the cuffs, the reinforcement and the zippers, not only the fabric name.

Layering underneath

The RYA's advice for yacht sailing is to dress in layers:

Base layer

A light layer next to the skin. Gill describes it as a wicking layer that moves moisture off the skin.

Mid layer

A fleece or jumper. Gill describes it as a breathable, quick-drying insulating layer.

Outer layer

A waterproof, hooded jacket. Gill describes its own outer layers as totally waterproof, windproof and highly breathable, though the page gives no test data.

The RYA also suggests a hat and sunglasses on a retainer, and sunscreen whatever the weather, because the sun's effect is stronger on the water.

For small boats where you expect to get wet, wetsuits and drysuits replace much of this system; see dinghy clothing. Boots that seal over foul weather trousers are covered under footwear and gloves, and our foul weather gear guide sorts the options by use.