What to Wear on a Boat: Layers, Shoes, Sun and Cold

Why It Is Always Colder on the Boat

Three things conspire. First, the water. In most cruising areas the sea surface is several degrees cooler than the afternoon air in spring and early summer, and the air a metre above it takes its temperature from the water, not from the land. Second, the boat moves, and moving air cools you. A sailing boat making 6 knots (11 km/h) into a 10-knot breeze puts 16 knots of apparent wind over the deck, which on a 15°C day feels closer to 10°C on exposed skin; a powerboat at 25 knots does far worse. Third, you are wet, or at least damp, from spray, dew or sweat, and wet skin sheds heat many times faster than dry.

None of this shows on a forecast. The forecast is for a sheltered station ashore at head height, still, dry. Hence the rule: read the shore forecast, subtract 5 degrees, add the wind, assume spray. If the day turns out warm you take a layer off and lose nothing. If you packed for the car park you are cold for six hours with no way to fix it, and a cold crew member is a slow, clumsy, seasick one.

Cotton Is the Enemy

Cotton absorbs water into the fibre itself and holds it there. A cotton T-shirt that gets a dose of spray at 10:00 is still wet at 16:00, because the breeze that dries a synthetic shirt in twenty minutes merely chills the cotton one. Wet cotton against skin is a heat pump running the wrong way, and jeans are the worst case: heavy, slow to dry, and wet from the cockpit seat within the hour on any boat that heels or throws spray.

Synthetics (polyester, polypropylene, nylon) hold almost no water in the fibre, so moisture moves through them to the surface and evaporates. Merino wool absorbs some but keeps insulating while damp and does not smell after three days, which matters in a small cabin. Either works. Cotton does not, and that includes the hoodie, the socks and the underwear.

Foul Weather Gear: Coastal or Offshore

Foul weather gear, oilskins, waterproofs: the shell layer. It splits into two grades and the difference is how long you will be wet for.

Coastal gear is for day sails, weekends and short passages where the cabin is a few steps away. It is lighter, more breathable and more comfortable to move in, with a hood, a decent collar and adjustable cuffs. It is what most people on most boats need, and a coastal jacket over a fleece covers a powerboat crew and a fishing crew as well as a sailing one.

Offshore gear is for sitting on a wet deck for a four-hour watch, night after night. Heavier fabric, fully taped seams, a high fleece-lined collar that comes up over the chin, a stiffened hood with a peak that turns with your head instead of blinding you, reflective patches, and reinforced seat and knees because that is where offshore gear wears through. You pay for it in weight, bulk and sweat on the warm days.

Whichever grade, if the budget only stretches to one piece, buy the bib trousers first and the jacket second. Rain falls on your shoulders for minutes; you sit in water for hours. High-cut bibs with a fleece back panel keep your core dry and warm from the cockpit seat up, and a cheap windproof jacket on top of dry bibs is a far better outfit than a fine jacket over soaked trousers.

Shoes: Non-Marking, Closed Toe

Deck shoes have two jobs: grip a wet, sloping deck, and leave no mark on it. Both come from the sole. It should be soft rubber that stays flexible when cold, with fine razor cuts (siping) that squeeze water out from under the foot the way a car tyre does, and it must be non-marking: a light colour, or a compound that does not leave black streaks on white gelcoat. Running shoes with a hard black sole scuff a deck in a morning, and on a charter boat that costs someone the cleaning deposit.

Toes stay covered on deck. A cleat, a running anchor chain, a dropped winch handle and a stanchion base are all at toe height, and a broken toe on day one ends a week. This is why flip-flops are banned on many boats, and not only for the toes: they have no grip on wet fibreglass, they come off at the first step down a companionway, and they float away when they go. Wear them from the dinghy to the beach bar and nowhere else.

For cold and wet, sea boots: rubber or waterproof-fabric boots to mid-calf with the same soft non-marking sole, sized to take a thick sock and loose enough to kick off in the water. Bare feet grip well on a dry deck and badly on a wet one, and give you nothing against the chain; acceptable at anchor in the tropics, not under way.

Sun: You Are Being Lit From Two Sides

Water reflects a meaningful share of the ultraviolet that falls on it, so on a boat you are exposed from above and from below at the same time, with no shade unless the boat carries a bimini and a breeze that hides how hot you are getting. The underside of the chin, the nose, the tops of the feet and the back of the hands burn first, and a sunburnt crew member on day two is a miserable one for the rest of the week.

• A long-sleeve UPF shirt (UPF 50 blocks about 98% of UV) beats sunscreen on the arms and shoulders: it does not wash off, it dries fast and it is cooler than bare skin in a breeze. A hooded version covers the neck.
• A hat with a strap. A wide brim for the ears and neck, a chin strap or clip because the first gust takes any hat without one. The bag-of-lost-caps at any marina office is the evidence.
• Polarised sunglasses on a retainer. Polarised lenses cut the reflected glare off the surface, which is what lets you read the water for depth, weed, moorings and the anchor going down. The retainer is because sunglasses sink. Many experienced crews carry a cheap second pair.
• Sunscreen for the face, ears, hands and the tops of the feet, reapplied, and reef-safe where you are swimming. Lip balm with SPF; lips burn.

Cold: Wind Chill, Hands and Head

Cold on a boat is mostly wind. Six knots of boat speed into a modest breeze produces a steady 15 knots (28 km/h) of wind over the deck for the whole passage, and the standard wind chill tables put that combination, at 10°C air temperature, in the region of 6°C on exposed skin, with the exact figure depending on humidity and how wet you are. It never stops, you cannot step out of it, and it works on the parts of you that are out in it: hands and head.

The head first. A beanie under the hood, or a fleece-lined hat, costs nothing in bulk and changes the whole day; a neck gaiter or buff closes the gap at the collar where the wind gets down your back. Then the hands. Cold hands stop working, and the hands are what handle the lines, the throttle and the anchor. Sailing gloves with reinforced palms and open fingertips are for grip and rope burn in mild weather; for cold, a waterproof insulated glove, plus a dry spare pair in a bag, because the first pair will be wet within an hour. Thin liner gloves under waterproof mitts are the warmest arrangement for a night watch.

Feet are the third extremity: two pairs of wool or synthetic socks in sea boots with room to move the toes. Tight boots are cold boots. And the dry bag, the one with the spare base layer, spare socks and spare gloves in it, is not an offshore luxury. It is the difference between a wet dawn fishing trip and a ruined one.

The Lifejacket Goes Over Everything

Whatever else you are wearing, the lifejacket goes on last and on the outside. An inflatable lifejacket worn under a jacket cannot inflate properly, and a foam one under a shell is a struggle to get to. Fit it over your thickest layer, do the crotch strap up so it cannot ride up over your head in the water, and check the cylinder and the firing indicator before the season. The RYA and USCG both recommend wearing a lifejacket on deck whenever conditions, darkness or your own judgement call for it; on a lot of well-run boats the rule is simpler and it is always. On passage at night or short-handed, a harness and tether clipped to a jackline comes with it. The full kit list is in our boat safety equipment checklist.

Three Different Bags for Three Different Days

A boat is not one activity. A powerboat day trip, a coastal sail, an offshore passage and a dawn fishing session are four different climates, and the bag that is right for one is wrong for the others.

The powerboat day is the one people get wrong most often, because it looks like a beach day. At planing speed the wind over the bow is 20 to 30 knots regardless of the weather, the spray is constant, and the run home into the afternoon breeze is cold in every month of the year. The windproof in the bag is what saves it. The dawn fishing trip is the opposite trap: the coldest hour and the hottest hour of the day on the same trip, so everything has to come off in stages.

What to Pack for a Charter Week

A bareboat charter cabin has a locker the size of a carry-on. Pack in one soft duffel bag that folds flat once empty; a hard suitcase has nowhere to go and lives on your bunk all week. For a warm-water week the list is short, and everyone who has done it comes home having worn the same five things:

• 2–3 quick-dry T-shirts and 2 pairs of quick-dry shorts
• 1 long-sleeve UPF shirt, hooded if you have one
• 1 fleece or light insulated jacket
• 1 lightweight waterproof, windproof jacket
• 1 pair of long trousers for cool evenings and ashore
• Swimwear, 2 sets so one is always dry
• Wide-brim hat with a strap; a beanie for night sails
• Polarised sunglasses on a retainer, plus a spare pair
• Deck shoes with non-marking soles, and sandals for ashore
• Synthetic or merino underwear and 2–3 pairs of socks
• Small microfibre towel (boat towels never dry)
• Reef-safe sunscreen, SPF lip balm, seasickness remedy
• Head torch with a red mode, for the deck at night
• A small dry bag for phone, wallet and passport in the dinghy
• Personal medication and a copy of your travel documents

For a cool-water or shoulder-season charter, add the coastal foul weather trousers and jacket, sea boots, gloves and a second base layer, and leave the second pair of shorts. Sailing gloves are worth bringing anywhere if you will be handling the sheets or the anchor chain. Most charter companies publish their own list; theirs will match this one with the addition of the boat papers and the deposit.

Comfort Aboard Is a Safety Item

A crew that stays dry and warm through the day arrives at the anchorage in a fit state to anchor properly, eat, and sleep, and sleep is the part that gets traded away first. On too many boats someone spends the night in the cockpit under a wet fleece, waking every hour to look at a shore light, because nobody trusts the anchor. That is the clothing problem moved after dark. A GPS anchor alarm on the phone or watch does the looking, and the crew goes below, into the bunk, in dry clothes. How to set the anchor so the alarm stays quiet is in our overnight anchoring guide.

The Bottom Line

You dress for the wind and the water you will be in, not for the forecast ashore, and it is always 5 degrees colder on the boat. Three layers with no cotton in them, a shell with a hood and a collar, bibs before the jacket if you can only afford one. Closed shoes with non-marking soles, a hat that cannot blow off, polarised glasses that cannot sink, gloves and a beanie in the pocket in every month. Lifejacket over the lot. Pack it in one soft bag, and pack the spare dry layer even when the sky is blue, because the sky is not where you are going.