Immersion Suits
A Boater’s Best Friend
Published: Saturday, December 6, 2025 10:00 am
By: Bruce Kemp
One of my biggest fears is falling off my boat in the middle of the night, in the middle of Lake Huron in the middle of October. The likelihood of a recreational boater being out in late fall conditions is pretty small, but some of us still go out. Hunters and fishermen are a different story; their activities are dictated by seasons and migratory patterns. Still, these individuals are on the water and are a substantial part of the number of yearly fatalities due to hypothermia.
In the United States, there were 556 boating fatalities in 2024 alone. Of those, 89 were directly attributable to hypothermia. Given that the USA has ten times the population of Canada, the number is actually quite low. However, one major factor in favor of surviving a dunking are the warmer waters of the Southern US.
A sudden dunking triggers the sudden-breath-intake reflex, which is part of the drowning process. Although not technically hypothermia, the cause is one and the same – a sudden shock brought about by exposure to frigid water. Water transfers heat approximately twenty-five times faster than air. Check the Clo value of any suit you’re considering — clo units are measurements of a garment’s insulation value.
The best way to avoid hypothermia is to stay home sitting in front of the fireplace with something good to drink. However, that’s not really an option if you want to extend your cruising season. Next best thing is to outfit yourself with a certified immersion/survival suit. There are a number of survival garments available. Let’s start with looking at what features they offer.
First, you need either a US Coast Guard or Transport Canada certification that the suit is rated as a Personal Flotation Device with hypothermia protection. Also, it should be SOLAS rated. SOLAS it the International Maritime Organization’s Safety of Life at Sea standard. This covers everything from PFDs to flares, EPRBs (Emergency Position-indicating Radio Beacon) to survival suits and how they are built.
Most elementary versions are the two-piece suits that look more like foul weather gear than true immersion gear. These come with a floater coat and bib pants, both of which have insulation and floatation properties. Although I wore a Mustang Cruiser Vest — a type of sleeveless floater coat — on a voyage from Toronto to Newfoundland years ago, I put it on mainly to stay warm while on watch, not in the water. Worked like a charm, and still this vest could have saved my life if I’d fallen overboard into the North Atlantic.
The benchmark suit on the Great Lakes is the classic Mustang MS 195 Integrity Flotation Suit. There have been a number of sinkings where the survivors attributed their survival to this piece of gear. Colored bright, survival orange or red they have a hood, Velcro closures at the wrists and ankles and cinch straps on the thighs and waist to prevent water warmed by your body from seeping out and cold water from the lake flowing in. There are also two SOLAS approved reflective tapes sewn onto the shoulders to reflect light at night making it easier for rescuers to find you. This suit lacks feet and gloves. I wear mine with a set of neoprene dive boots and gloves, but Mustang does make full-fingered gloves.
It’s been proven that one of the main areas where heat loss happens quickly is from a bare head. Doesn’t matter if you are bald or have a head of hair like Willie Nelson. You’re still going to lose heat, so the hood is your main line of defense. The Mustang floater suits work on the same principle as a wet suit. They trap a layer of water inside the suit and your body acts as the heater for it.
Once the water is warm, it stays that way if there is no inflow of cold water. If you fall overboard, the basic suit is not watertight. However, it is a more then excellent garment for cold weather sailing keeping you dry and warm in rain and spray conditions. Nice for early spring or late fall day cruises. For recreational boaters, these are excellent value for the money. Just be aware that a snow mobile suit is not the same thing and are dangerous around the water as they flood and drag the wearer down.
Full-body, industrial grade survival suits have integrated boots and an insulated hood, and many also come with integrated gloves. They are offered in two configurations: suits in which the fabric itself provides the insulation, and those that have a totally waterproof outer shell (AKA a dry suit) where you can put on multiple layers of warm clothing underneath it. I’d make my decision based on the worst-case scenario for what I’m doing — like having to abandon ship mid-storm on a late fall or early spring Lake Superior.
Neoprene immersion suits, like the Viking suits, are constructed with a neoprene fabric that provides its own insulation. These trap water in the insulating layer while keeping you dry. They’re a tighter fit than the dry suit to minimize water leaking in, but they are loose enough to move around comfortably in, and they’re designed to be put on quickly with minimal fuss. Most are brightly colored with emergency green being the preferred shade. The boots have a large footprint with anti-slip soles.
Dry suits are exactly what the name says they are. They provide a totally enclosed, layered environment. With tight closures at the throat, wrists and ankles the wearer can add insulated undergarments to the mix and stay both warm and dry. A hood or proper hat, gloves, and booties complete the outfit. Some of the better drysuits come with inflation tubes that can be used to blow up the suit to keep the wearer afloat. These are extremely popular with surfers, SUP paddlers, and dinghy racers as well.
tags: clo insulation value, cold water boating safety, cold water shock, cold weather sailing gear, dry suits vs neoprene suits, great lakes boating safety, hypothermia prevention boating, immersion suits, lake huron boating, late season boating safety, mustang flotation suit, overboard survival tips, solas rated gear, survival suits, uscg approved suits
