Sailing in hot weather can be fantastic- light airs, fluffy clouds, easy swells; but if you get it wrong in your packing hot weather can make you just as uncomfortable as cold weather. Whilst not strictly as technical to get right as cold weather preparation- here are some notes to make sure you get it right during your hot weather event.
Choosing the Right Materials
The main problem we have seen over the years when it comes to hot weather is an incorrect choice of materials in the clothing some crew members bring with them. It seems like the smallest detail but it can add up to a very enjoyable or downright uncomfortable event.
When we choose materials to take into cold weather as we discuss below we must ensure that base layers and mid-layers do not include cotton, wool or other natural fibres. Cotton is often called the ‘the killer cloth’ because it can hold such huge amounts of water. It then wrecks an otherwise perfect layering arrangement trapping sweat and externally introduced water in the system. Where cotton excels, however, is as a comfortable, lightweight fabric that feels good on the skin even in hot, sticky situations. It is possible in some new, highly technical situations like that at sea if you are not used to it, to put aside common sense that has come hard-won in your own life. Technical base layers are a perfect example of this. You know what to wear in hot weather- you’ve done this before. So don’t overthink it and turn up with only a range of polypropylene and polyester clothing that is going to be seriously itchy, uncomfortable and miserable after the first wearing. Just remember to take the cotton off if things get wet or cold.
Cotton may be awful as a base or mid-layer as it holds water and has too higher thermal conductivity but in hot weather, it is by far the comfier option.
Sailing in windy or cold weather requires all crew to have a minimum amount of warm and waterproof clothing with them to ensure they can face the elements at their best without becoming uncomfortable and ruining their experience or worse than that subject to hypothermia.
The best way to combat the cold and deal with increases and decreases in body temperature is by ‘layering’. Due to the nature of sailing, we may be inactive for long periods of time on watch then suddenly be asked to expend a lot of energy and whereupon we will heat up very quickly and start to sweat and overheat. Once we are inactive again our now wet clothes will not retain heat and we will start to cool uncontrollably- leading to a great deal of discomfort and potentially hypothermia.
In these conditions, it is essential to dress using an intelligent layered system that allows you to quickly regulate and stabilize your body temperature, and remain warm and dry whatever the conditions.
Base Layer – the key to warmth
Base layers are made of ‘wicking’ materials- that is materials that are not able to hold water very easily. During work cycles, any sweat or any water that has entered the clothing from outside is heated by the body and some volume of it becomes water vapour. As the base layer is unable to hold water easily the vapour is free to travel away from the body down the moisture gradient towards the outer layers of clothing. If the intermediate or mid-layer is also made of a wicking fabric the water vapour will pass through it without condensing back into water and pass onto the outer layer where; if the garment is functioning correctly the water vapour will pass out into the environment leaving the wearer and all base layers warm and dry.
Intermediate ‘Mid’ Layer
Mid-layers create a stable air pocket around the body which the body will then warm up very quickly. If the air pocket can be maintained and not lost to the outside environment the body will remain well insulated and comfortable. If however, the mid-layer becomes wet is too thin or cannot maintain its volume the body will not keep warm and the layering system will fail. By varying the thickness of the mid-layer the wearer can increase or decrease the ambient temperature he or she experiences. Fleece material comes in three thicknesses Polar 100, 200 and 300 a fact you can use to your advantage to create mid-layers of different thicknesses to suit your situation.
Varying mid layer materials and thicknesses will give you the temperature control you need.
Outer ‘Shell’ Layer
The Outer or Shell layer is the most obvious part of the system. For Ocean racing your shell layer is going to consist of a jacket or smock that is probably a lot heavier than any other piece of clothing you wear unless you are from the high latitudes. When the fabric the outer shell is made from is heavy and somewhat stiff the result is that the garment is more likely to resist being flattened over the body by wind and water pressure removing the insulative warm air pocket the mid-layers are designed to promote. Hence you will often see that offshore jackets differ from inshore jackets by this one important feature- their ‘face fabric’ is thicker. After that, all other features are somewhat standard in modern clothing from reputable manufacturers and will include brightly coloured full hoods, waterproof closures, retro-reflective strips, seals at the wrists, drawstrings to reduce water ingress and loss of heat, breathable fabrics and handwarmer fleece pocket linings.