Base Layers

Thermal base layers: materials and next-to-skin construction

A technical base layer should perform its function without adding unnecessary bulk beneath the layers worn over it. These first-layer garments use performance fabrics that combine low weight with thermal insulation. Quick-drying stretch fabric supports breathability and adapts to body movement thanks to its high level of elasticity.

One of the key features is the circular-knit construction, designed to retain warmth while wicking moisture away from the skin. A thermal base layer therefore addresses two needs that can alternate while sailing: helping retain warmth when needed and managing moisture during more active periods. Seamless construction further enhances the comfort of these base layers when worn directly against the skin.

Polygiene® technology is also incorporated directly into the yarn. North Sails uses it to help inhibit the growth of odor-causing microorganisms and keep garments fresher for longer.

How to choose thermal underwear for sailing

When choosing the first layer of a layering system, consider which areas of the body need coverage and what will be worn over them. The Performance base layer top pairs seamlessly with the matching technical leggings for a complete first-layer set. Both use quick-drying stretch fabric, seamless construction and Polygiene® technology.

It is equally important to consider the layers worn above the base layer. The first layer performs a different function from a mid layer: thermal underwear sits next to the skin to help manage warmth and moisture, while intermediate layers can provide additional insulation according to the conditions.

When greater insulation is needed, the system can be completed with a sailing fleece. This allows each layer to perform a specific role rather than relying on a single garment to meet several different needs.

From base to outer shell: mastering sailing layering

Wearing multiple layers makes it easier to adapt base layer clothing to changing temperatures and activity levels on board. The base layer forms the foundation of the system: it sits beneath the other garments, with one or more additional layers added according to the level of insulation and protection required.

For the upper body, a thermal shirt or long-sleeve base layer can be paired with a mid layer or fleece and, when an outer barrier is required, a sailing jacket. The appropriate jacket depends on the type of protection needed, while the base layer continues to perform its role underneath the other garments.

The same principle applies to the lower body: thermal leggings or base layer bottoms can be worn beneath sailing pants to create a combination that can be adjusted according to temperature. Building a layering system around technical thermal underwear makes it possible to add or remove subsequent layers while maintaining the moisture management and freedom of movement provided by the first layer.