The three layer technique is an accepted and proven principle, widely incorporated into the design of specialist clothing – and chosen by discerning outdoors enthusiasts. Based on a simple principle, water transmits heat thirty times faster than air. So wet skin gets cold thirty times quicker than dry skin. To keep warm in the worst conditions, first of all, you must keep dry!
The theory behind the layering system is that several thin layers of clothing will keep you much warmer than a single thick layer. Layering works by creating air spaces between garments to trap warm, still air, creating a microclimate that surrounds your body. You can adapt this to deal with temperature, wind, moisture and exertion levels; if you are feeling cold add a layer, if you feel hot, take a layer off.
To do this your fishing clothing must:
- Transport body moisture away from the skin
- Hold dry warm air close to the body
- Keep the rain & snow out
BASE LAYER (LAYER 1)
The base layer is critical and it should transport moisture away, keeping the skin dry, dispersing it to the air or outer layers so that it can then evaporate. Modern synthetic fibres such as polypropylene and polyester make the best base layers. They are lightweight and strong and dry quickly.
MID LAYER (LAYER 2)
The Mid Layer works as an extension of the Base Layer, continuing the transportation of moisture from the Base Layer and providing an insulation barrier to retain your body warmth. Selecting layers with varying insulation properties can therefore readily control body temperature.
OUTER LAYER (LAYER 3)
The outer layer, or shell, is your principal barrier from the elements. It should allow air to circulate and permit moisture to escape. For dry conditions, an uncoated, breathable wind resistant shell or a smooth-surfaced soft shell type jacket is generally sufficient. When it’s wet, you will need to choose a technically designed waterproof jacket. Breathable or Gore-tex which offers protection from wind, rain and snow yet allows moisture vapour to still escape through its membrane.
One final but easily forgotten point – head, hands and feet. It’s easy to forget about hats, gloves and extra warm pair of socks. Up to 40% of the body’s heat can be lost through the extremities.
Waterproof, breathable outdoor fishing clothing has a durable water-repellent (DWR) finish applied to the outer surface. This makes the water bead up and roll off, rather than soaking into the fabric. If the water is allowed to soak into the fabric it will impair the breathability. If the breathability is impaired, condensation will build up inside the garment, so although still waterproof, the wearer will get wet. This DWR finish is not permanent. Over time, it will start to fail, and the garment will start to absorb the water. This is known as wetting out.
Several factors will affect the DWR finish:
- Dirt attracts water and will mask the DWR finish. (Detergent residue has the same effect.)
- Washing the garment in detergent will actually remove the DWR finish. Liquid detergents and biological detergents tend to be the worst.
- Flexing and abrasion will also cause misalignment and removal of the DWR finish