Using Heated Undersuit Systems

Using Heated Undersuit Systems

I remember a few equipment milestones in my diving career that made the whole diving experience much more enjoyable. One of them was a drysuit - they are much more accessible nowadays, but a few years back many divers still scuba dived in cold waters in wetsuits. Using a drysuit together with an appropriate undersuit, in my case, allowed me to extend my dive times by at least a threefold and dive safer. Sometimes I wish I had some of the latest diving equipment back in the day - it would definitely make my diving experience in the Atlantic or the Baltic Sea much more enjoyable. 

One such item rising hugely in popularity is a heated diving undersuit garment. Like in any extreme sport, the right type of equipment is the key to success. Even the best drysuit will not perform to the fullest without a good quality undersuit. Besides, if you own a good quality undersuit and engage in cold water diving, you will quickly find out that a fully heated undersuit or a heated vest will take your diving up yet another level.

Nobody can cheat physics, and at some point, if you stay longer underwater, hands and feet get cold, keeping breathing rate steady becomes tough, or the dreaded urge to pee emerges. I experienced it all and, most likely, so did you. Usually, they are telltale signs that your thermal protection is not up to the job. Apart from the comfort aspects, there are more serious health and safety implications of an excessive cooling down while scuba diving. Your movement dexterity decreases significantly making simple manual tasks, like operating your inflator buttons or deploying your SMB much more difficult. Some argue that feeling cold makes you more prone to nitrogen narcosis, which reduces your perception of the surrounding environment and can impair your decision-making process. Most of all if your body is too cold, blood circulation is weaker, your body less effective, and as a result, you increase the risk of decompression illness due to inadequate off-gassing.

Someone once said, "necessity is the mother of all inventions." This saying could not have been any more appropriate in scuba diving. There is nothing better than keeping your hands and feet comfortably warm through the entire dive. The most recent research into the connection between thermal stress and decompression illness suggests that maintaining the cool-warm ratio of your diving profile reduces the risk of decompression illness during scuba diving. This means staying adequately cool on the descent and bottom while keeping comfortably warm during the ascent and decompression works the best. It is necessary to mention that overheating is deemed as much dangerous.  Excessive heat during and after your dive can contribute to the decompression illness as much as the extreme cold. Modern heated vests, undersuits and gloves are the ultimate tools in assisting in proper thermal regulation throughout the dive.

How does a heated undersuit work? 

There must be something electrical in it, but electricity and water do not go well together, so what's the deal? The heating undersuit, vest or gloves are made out of high-quality heat compatible fabric, which in itself has thermal properties and will keep you warm if the battery is off. What makes heated undersuit stand out from the standard exposure protection is a network of battery-powered heating wires woven into the fabric in strategic places to keep your body warm. Heating wires are usually made out of high tech non-metallic material or metallic cables coated with a special break-resistant and waterproof silicone. For the best effect, heated undersuits and heated vests should be used in combination with a base layer or an undersuit and not on bare skin.

There are two main types of heated undergarments. The first type has batteries integrated and kept under your drysuit like our Thermalution line of products. The second type of heated undersuits employs external battery pack where power travels to your heated undersuit with a cable through the thermovalve in your drysuit - like our SANTI line of products. 

Heated Undersuits with integrated batteries

The Thermulation is famous for its heating vests, undersuits and gloves. Their system consists of batteries that are mounted in a pocket directly on your undergarment. The Thermalution's heated diving undersuits have non-metallic cables woven into the fabric in the most strategic places to keep your body warm. The Thermalution's heated undervests have a large panel to keep the core temperature, while the Full Red Grade heated undersuit offers heating panels on the torso as well as thighs. Your Thermalution heated undersuit, heated vest are controlled by a convenient wireless remote mounted on your hand. The Thermalution system is also upgradeable, so if you already have their vest or undersuit, you may now add on heated gloves. Some may argue that having a chemical battery mounted near your body can be disadvantageous. Still, selected Thermalution models are waterproof and suitable even to be worn in combination with your wetsuits! Another possible disadvantage is that internal batteries have to be smaller by design and therefore may not provide sufficient runtimes for longer dives, in which case the undersuit with external power source can be more appealing.

Related heated garments: Stand Alone Heated Gloves, Heated Undervest, Thermalution Heated Suit.

Heated Undersuits with the external power source

Born in the freezing waters of the Baltic Sea SANTI is the market leader in heated undersuits, heated vests and heated gloves. Their undergarments are popular amongst recreational, technical divers and explorers and characterised by an external power supply. A lot of divers argue that the external power supply is safer and more practical. Safer because in case of an emergency, you can disconnect the battery. More practical, because the system is considered modular and from one large battery like SANTI 24Ah battery pack, you can supply multiple heated garments for longer. Furthermore, the external battery enables the use of other diving tools like an umbilical diving torch, making the whole system more versatile. The downside of this system is that you need to purchase a battery pack separately and therefore makes this type of a heated undersuit more expensive.

Related heated garments: Heated UndersuitHeated VestHeated GlovesThermoconnector, Thermovalve, 6Ah Battery Pack24Ah Battery Pack, Dry Gloves.

Which type of heated undersuit is for me? 

The modern heated undersuits have a higher price tag than your standard undersuit, but they pack a lot of technology in return. A lot of recreational divers will opt for a combination of heated vest or heated gloves or both to complement their conventional undersuit. This may be a good option for someone who is looking for a little bit of extra warmth on the torso, back and hands during recreational dives in cold waters. Sometimes just having your hands toasty warm makes a massive difference so heated gloves may be suitable for someone who enjoy full dexterity but not looking for the full heated undersuit.

However, if you are engaging in longer, deeper technical diving, the full heated undersuit will be more suitable for providing thermal comfort consistently from your neck down to your ankles. You may also consider an undersuit that will perform for the full duration of your dive. In this case,  fully heated undersuits with external battery may be more suitable for the type of diving you do as their operation times can reach even few hours. 

Mike's Dive Store is all about providing the best exposure protection for the type of diving you do. If you have any questions or you are not sure which heated undersuit to choose, do not hesitate to get in touch