Exposure Protection 101 – Diving in Alberta - and anywhere else in cooler water
By Mark Faas & Connie Faas
Introduction, by Connie:
As land-locked prairie divers, we celebrate what makes cold water diving the best:
The chilliness of the waters is balanced with the warmth of new friendships made. We dive with many new dive buddies who quickly become friends upon sharing these adventures.
As David and I bask in the memories of these adventures, and share pictures, we want to assure all divers that cold water diving can be done in relative comfort. Trust us, if it was not fun, we would not do it! Warm water, tropical diving is easy to love: this is about having a love of cold water diving. Enjoy the primer that follows, by Mark, as he reveals the secrets and tricks of the trade to enjoying cold water diving.
Exposure Protection 101 by Mark Faas:
Water conducts heat 20 times faster than air, so all water feels much colder than air at the same temperature. Divers must choose their exposure protection carefully to have a comfortable dive.
This article will discuss the most common choices for exposure protection locally, and considerations for when to choose them. Additionally, there are several factors which modify how much insulation (underwear) is required, and options for this as well.
By far drysuits are the most common option for divers in Alberta, even for new divers.
At its most basic, a drysuit has an outer layer which prevents water from getting into the suit, and an inner layer of insulation which provides thermal protection.
The diver will add air to compensate for suit squeeze as they descend (which also affects buoyancy). Drysuits are versatile because you can manipulate the inner layer to provide more (or less) warmth depending upon the dive you are planning and surface conditions.
As for learning how to dive in a dry suit, it is not more difficult than a wetsuit, it is just different. A dry suit course will guide you through the skills such as buoyancy characteristics. Many of our student divers learn in a dry suit, beginning with their confined water dives.
The other option for exposure protection is a wetsuit. These are made from neoprene and work by preventing the water from moving around you as you swim. In Alberta, this typically is a 7 mm thick, two piece farmer john style wetsuit.
WHEN TO CHOOSE A WETSUIT
Diving in a wetsuit is an option. In Alberta, typically, this will be reserved for the warmer summer months (July, August, and early September). With a wetsuit that fits well, you can be as warm as someone diving in a drysuit, particularly for the first dive. Getting into a wet wetsuit for the next dive is a less comfortable experience, but not usually a problem on a warm day.
WHEN TO CHOOSE A DRYSUIT
Drysuits are great for all water temperatures we commonly experience in Alberta. The warmest water conditions we typically experience are in late July/early August when water temperatures may rise as high as 20C (68F) at the surface.
In this case, the diver will have a thin base layer under their drysuit (for example, the Aqualung MK1 fleece liner). On a hot day, you can expect to be a bit warm before you get into the water, but comfortable in the water. You may choose to wear wetsuit gloves, or no gloves at all.
As the water temperature drops in September (or June), you will likely choose a thicker base layer (ie. the Aqualung MK2). You will certainly want a hood (typically a 5 mm neoprene hood), and probably dry gloves with a medium weight glove liner. You’ll also want warm socks! This level of exposure protection is what most local divers will start with, as it is versatile, and can be used in the summer months (omit gloves/hood), or colder months (add more base layers, shorten dives).
For comfort in colder months like May & October, you will want more layers under/over your MK2, or underwear such as the Aqualung Thermal Fusion. You will also want the best socks you can get!
The coldest times to dive are the few weeks after the ice comes off the lakes, or before the ice goes on. Here you’ll want every layer you own! You may even want heated clothing, such as the Thermalution vest or Light Monkey heated vest. The thermocline will disappear and the water temperature is usually a consistent 4C from the surface to the bottom of the lake.
Finally, there is ice diving! We don’t get to go ice diving often, but when we do, we are rewarded with fantastic vis. and an incredible story of bragging rights!
You might think we wear even more insulation, but actually, the water doesn’t get any colder (otherwise it is ice!). As w ell, the dives are shorter. All this means you’ll dress with more concern for the air temperature than the water temperature.
OTHER FACTORS THAT AFFECT WARMTH WHILE DIVING
People do polar bear plunges in the middle of the winter (or above the Arctic circle). So one might ask if they can do that, why can’t I dive in a Speedo?
Here are a few of the factors which will cause you to add or remove exposure protection:
Length of dive - the longer you are underwater, the more time you’ll be losing heat for. This is one of the main reasons you can actually wear less insulation for an ice dive than a late season open water dive.
Activity Level - will you be swimming hard, or barely moving? Activity generates heat and will affect how much insulation you want.
Metabolism - if you are hungry, you are more likely to feel the cold. As well, some people generate more heat than others, or are more comfortable in a cooler environment.
Body Shape - A large round object will lose a smaller proportion of heat to the environment than a short thin one. Same thing applies to humans!
Should you have any questions about exposure protection, please ask Mark firstname.lastname@example.org, or Connie email@example.com, at any time.
By Mark Faas