Cold weather and life rafts

It has been quite cold here in the Pacific Northwest. You don’t have to go very far to get in to single digit territory which brings up the question of what conditions a life raft will operate in. As some of us remember from physics, everything else being the same the pressure of a gas will decrease as the temperature decreases. Since life rafts like to have around 2 psi of gas pressure, as it gets colder the amount of gas needed to reach that pressure increases.

Commercial life rafts are designed to work down to minus 20 degrees Fahrenheit. Rafts designed for recreational boats tend to have their lowest working temperature much higher, somewhere between plus 10 degrees to plus 40 degrees.

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So what happens if your raft isn’t designed for the temperature range where you will be operating? Nothing good! If your raft is able to deploy itself out of its container or valise it will not fully inflate and will take a long time even getting to that point. Worse yet it might not inflate enough inside the container (or valise) to even deploy leaving you swimming in very cold water.

For most vessel operators really cold weather is not an issue. Wintertime is for skiing or trips to the sun, not boating. Still there are some of us who find being on the water in the winter really beautiful and without the crowds that sunshine brings. This group needs to be concerned and choose the right life raft. USCG approved commercial rafts are a great choice but tend to be pretty large to fit on recreational boats. Switlik’s new Offshore Passage Raft and Coastal Passage Raft also provide excellent cold weather inflation since they use high pressure air rather than carbon dioxide as their inflation gas. With high pressure air you get inflation times that do not change much as it gets colder. My guess is this is the raft Santa uses on his sleigh and the really good news is the material it is made out of is tough enough that reindeer hooves should not pose an issue.