The Case for Merino in Drysuits

Merino™ has been proven over time to be the best lining possible for wetsuits. It adds 35% more thermal efficiency to the suit, makes it easier to slide the suit on and off, reduces odor, inhibits bacteria growth, and is a non- petroleum based renewable natural resource. It adds thermal efficiency through its exothermic properties, by helping to reduce water transfer, and by holding a greater volume of body-warmed water next to the diver.

But how does Merino™ benefit the drysuit diver?

Merino™ has benefits to the drysuit diver when applied to the undergarment as well as to the drysuit itself. Diving in either a Merino-Evolution Undergarment or in a Black Ice Drysuit is warmer and more comfortable than any other product, but using both together compounds the effect to create the warmest, driest, most comfortable drysuit diving ever.

The use of Merino™ in the Merino-Evolution Undergarment benefits the diver in several ways: comfort, hygiene, insulation value, and perspiration wicking. The Merino™ lining of the Black Ice adds greater insulation and moisture control, which leaves the diver drier and warmer.

When worn close to or against the skin, such as in an undergarment, Merino™ is very absorbent, which is why it is often used in extreme sport clothing. This helps the diver stay more comfortable by drawing perspiration away from his skin. A drier diver is warmer and less subject to wind chill from air movement within the suit.  Because Merino™ does not promote the growth of bacteria, it is cleaner and less likely to promote odor.

Most obviously, adding a layer of Merino™ is like wearing the finest sweater you’ve ever owned, making the undergarment much warmer. In fact, the addition of Merino™ to the Evolution Undergarment increases its TOG rating from 3.5 to 4.5, meaning that this addition results in a 29% more efficient undergarment.  

In the Black Ice Drysuit, the Merino™ lining works on similar principles. Most obviously, by adding a layer of wool insulation to the inside of the drysuit, we have increased the thermal barrier between the diver and the outside water. This makes the drysuit itself that much better of an insulator, and therefore far warmer than a traditional shell- type suit or a non-Merino™ lined neoprene suit.

Secondly, and more importantly, the addition of the Merino™ layer absorbs moisture in the air, compounding the wicking ability of the undergarment, and leaving the diver’s skin much drier.

Once a drysuit has been closed, water and water vapor can no longer escape. Even in a perfectly dry and sealed suit, the interior of the suit quickly becomes a very humid environment due to the diver’s perspiration throughout the dive, which can easily be as much as 1 cup (8oz.) of water. This is an amount of water that is easily absorbed by the amount of Merino™ on the interior of a Black Ice suit. In a conventional suit, this perspiration condenses inside the suit, creating a dampening effect on any undergarment or clothing, which greatly reduces the insulating ability of the undergarment. Any experienced drysuit diver knows the feeling that there is a leak in his suit, only to find later that it was merely the condensation on the interior of the suit. When warm, moist air hits the cool material of a traditional suit, the vapor condenses into water. This water runs down along the inside of the suit, pooling along the front of the suit while in a diving position, and then in the feet when the diver climbs back up onto the boat or beach, resulting in a damp, clammy diver.

However, in the Black Ice Drysuit, that same water vapor is absorbed into the Merino™ lining and is locked away from the diver’s body, both during and after the dive.  Merino™ holds more than 35% of its own weight in water without feeling damp, ensuring that the thermal efficiency of the suit and undergarment is maintained. Additionally, the mere act of Merino™ absorbing moisture triggers an exothermic reaction in the wool, emitting a small but measurable amount of heat back to the diver.

Also, while the Black Ice does provide as much as 11% more actual insulation than a drysuit made of the same material without Merino™, the psychological effect of staying in a truly dry environment makes divers feel much more comfortable, allowing dives into colder water for longer periods of time. After the dive, when the suit is opened and the internal humidity drops, the scales on the Merino™ fibers open up, allowing the absorbed liquid to quickly evaporate, ensuring a warm and dry second dive.
Merino’s structure produces an elegant combination of water repellence, breathability, and moisture absorbency.  In short, for the small incremental investment made while obtaining Merino™ lined drysuit products, divers get the opportunity to make longer, better dives into colder waters, getting the most for their money.