What to wear whale watching in Iceland: the overalls cover less than you think

Base layer. Thermal or merino, not cotton. This is the layer people get wrong: a cotton t-shirt holds sweat from the walk to the harbour and then chills you for three hours.

Mid layer. A fleece or a wool jumper. The overalls are windproof but they are not especially thick, and the insulation has to come from what is underneath.

Hat. The single most important item you bring. Fitted, covering the ears, and not loose enough to leave in a gust. A hood is not a substitute: it flaps, it blocks your peripheral vision and you cannot hear the guide.

Gloves. The second most important, and the one people forget. Bare hands on a cold rail for three hours is what sends people into the saloon at the exact moment a whale surfaces. Thin liner gloves let you work a camera; take a warmer pair as well.

Shoes. Closed, flat and preferably waterproof. Decks are wet, spray reaches the lower deck, and open shoes are an accident waiting for a swell.

The wind is the temperature. Icelandic air temperature is milder than most visitors expect — the Gulf Stream keeps Reykjavík around freezing in January rather than well below it. What makes the deck cold is wind chill, and a boat moving at ten knots creates its own wind on top of whatever the bay is doing. Windproofing beats bulk.

Spray is salt. On a RIB and on the lower deck of a big boat, spray reaches you. It is salt water, so it does not evaporate cleanly — keep cameras in a pocket between sightings and wipe lenses with a proper cloth rather than a sleeve.

The light is low and bright at once. In winter the sun sits just above the horizon for the whole sailing, and in summer it barely sets. Either way you are looking at glare off water for hours. Sunglasses are equipment here, not a fashion decision.

Faxaflói is shallow. Shallow water makes a short, steep, quick swell rather than the long ocean roll people are used to from ferries, and that frequency is exactly the one that upsets the inner ear.

Three things help, in this order. Take something on the dock, half an hour before sailing — tablets do very little once you already feel ill. Stay outside, looking at the horizon: the warm saloon with its diesel smell and its rocking window frames is the worst place on the boat. And stand amidships rather than at the bow, where the vertical movement is greatest.

The counter-intuitive fix is the boat itself. A rigid inflatable rides over the same swell instead of rolling through it, you are in cold fresh air the whole time, and you are looking forward at a fixed horizon. People who dread boats often do better on a RIB than on a big steel hull, and any operator here will tell you the same.

If you know you are susceptible, book a morning sailing in summer: the bay is calmest before the afternoon wind, and a calm Faxaflói is genuinely flat.