Drysuits 101: Everything You Need to Know

Everyone knows what a wetsuit is. But drysuits? They can be a bit more of a mystery for new divers. But when it comes to diving in cold waters like we have in Vancouver, drysuits are the norm. Why do we use them? What are the main types? And what is it like diving in them?

This overview is meant to give you a clearer sense of what a drysuit does and what to expect when you start learning. It is not a substitute for proper training. If you have never used a drysuit before, make sure you get drysuit certified before heading out on your own!

How is a Drysuit Different from a Wetsuit?

A drysuit is a full, one-piece suit that seals water out, and creates a layer of air around your body. Only your hands and head are exposed, and most divers add thick hoods and gloves to stay warm. The air inside the suit provides the insulation. A wetsuit relies on a thin layer of water that your body warms up, but because you are still wet, you cool down over time. 

Staying dry helps you stay warmer for longer, but that still depends on what the water temperature is and what undergarments you are wearing. In Vancouver, divers usually wear thick, warm layers under the suit to stay comfortable. Several brands make layers specifically for this purpose.

The extra challenge is buoyancy. The trapped air inside the suit is buoyant, and the undergarments also add buoyancy, which is why a Vancouver drysuit diver often carries twenty-eight to thirty-eight pounds of lead (more than double what you would normally need in warm water).

It is worth noting that this is an element of drysuit diving that doesn’t exist in wetsuit diving. Learning the way the air moves inside the drysuit takes a bit of practice. Air can move freely around the suit. It can settle in your arms, legs, or feet depending on your position, so controlling it is as much about movement as it is technique.

At the start of the dive you vent almost all the air, and as you descend whatever remains compresses and the suit squeezes against you. You add just enough air to reduce the squeeze and stay warm and manage your buoyancy. 

Most drysuits only have one deflate valve on the shoulder, and you cannot vent the suit unless the air reaches that point. During drysuit certification, you’ll learn simple techniques for venting, as well as some personal preferences on how you set your vents. 

Different Types of Drysuit Explained

Drysuits come in a few main styles. Shell suits are the most common today. They are made from laminated materials such as nylon, Cordura, or Kevlar. They are lightweight and tough, and they do not change buoyancy much at depth, though they rely entirely on your undergarments for warmth. 

Neoprene suits are thicker, warmer, and extremely durable, but standard neoprene compresses as you descend, which reduces buoyancy and insulation. Compressed neoprene suits try to solve this by squishing the neoprene down so it behaves more like a shell suit while still giving you some warmth. They are heavier and usually more expensive, but very comfortable and hard-wearing. 

Vulcanized rubber suits are less common for recreational divers but are standard for commercial work because they are heavy, tough, and easy to clean.

Developing Good Drysuit Diving Habits

Diving a drysuit becomes easier once you develop a few habits. The first is always knowing where the air is. Air moves upward, so your body position determines where it collects. If your hands are above your head, the air moves into your wrists. If it collects in your feet and you do not move it back toward your shoulders, it will eventually try to pull you upside down. 

The second habit is staying ahead of buoyancy changes. If you start to ascend too quickly, the expanding air has to travel the entire length of your suit and all your layers before it reaches the dump valve, and that takes time. Small, early adjustments make everything easier. 

The third habit is using your body actively. Controlling a drysuit is not passive; your core, legs, and finning all help move the air where it needs to go. 

And of course, the best way to improve is to dive often! Get in touch to learn about drysuit certification, or if you are new to drysuit diving join us for an upcoming trip!