Manual vs. Automatic Inflatable Life Jacket / Safety Harnesses

Posted by Darrell Nicholson at 01:55PM - Comments: (12)


As a follow-up to last week’s blog post on safety tethers, it is important to note that these devices are just one component in a system that includes the jackline and a safety harness (typically combined with a personal floatation device, or PFD) and that these components should be evaluated together as a whole. We looked at jacklines in April 2007, and we tested inflatable life jacket-safety harness combos in two different issues, December 2006 and August 2008. The type of harness you have is particularly important when considering tethers.

Practical Sailor tested tether release functions in the water.

One of the chief questions about an inflatable PFD-harness is whether you want an auto-inflating PFD or a manually inflating model. (Some sailors prefer just a harness without any integral flotation, also an option.) The auto-inflating devices are activated by water or pressure change; manual-inflating devices require the wearer to pull a lanyard. Commonsense would suggest that an auto-inflating harness/life jacket is the best choice for the cruising sailor. Afterall, if the sailor is knocked unconscious, he or she will be unable to manually inflate the PFD.

However, there are cases in which an inflated harness can be a hindrance—for example when you are trying to climb back aboard under a lifeline, or dive free of debris or rigging. And as our tests have shown, rain and waves can inflate some models, a nuisance that could interfere with managing the boat.

An inflated PFD can also interfere with releasing from the tether. Ordinarily, you would not want to release yourself from your tether, but there are cases in which it is better to cast yourself free from the boat, or you risk drowning. Several crew who survived the capsize of Wing Nuts in this month’s Chicago-to-Mackinac race were forced to detach themselves. One, Stan Dent, had to cut himself free. The captain and crew who died, Skipper Mark B. Morley and Suzanne Bickel, were still tethered to the inverted boat. The circumstances surrounding their death are still being investigated, but so far, no official reports link their deaths to an inability to release from their tethers.

Typically, the tether attaches to the harness/PFD with a snap shackle that is released by pulling a small lanyard. As we’ve found in past testing, trying to locate a small tether and apply 30 pounds of pull while you are being dragged by a boat is no easy task. Trying to perform this task while you are being hugged by two inflated balloons is even harder. The inflated panels of the life jacket can obscure the tether lanyard, making it harder to locate and pull.

Bottom line: If you use an inflatable PFD/harness, test your ability to release yourself with the PFD inflated and uninflated. As I mentioned last week, a quick and easy check of the release mechanism in your tether is to apply as much body weight as possibly on the tether and try to release yourself. As a last resort, have a sharp knife ready to use, preferably a fixed-blade or one that can be easily opened with one hand. (Our most recent broad knife test was in March 2004.)


Comments (12)

Fortunately, I have only once found myself under a capsized boat (31' trimaran, 25 mi offshore in 10 degC water) with an auto-inflated PFD, but here's what I learned. The PFD helped to hold my head up in the trapped airspace under the cockpit after I fell into the water and the boat capsized on top of me. I had some difficulty releasing the Gibbs hook on my tether, but that was due more to unfamiliarity with the hardware than because of the PFD. It is not necessary to swim down to get out from under the boat - I just pushed up on the hull and net and walked with my hands to the edge, just like my USAF water survival training for getting out from under a parachute. Once on top, I was able to reach through the net to recover my tether, and once looped around the daggerboard to clip on itself was invaluable for keeping me and the crew (who all clipped to the loop of my tether) safely on the boat. At no time did I lose contact with the boat or become separated from it, as could have happened if I was swimming. The forest of lines dangling from the overturned hull was a bigger hazard - always wear a knife on your PFD harness. You do have to make your decision on which type of PFD based on the odds, and for me the chance of being knocked unconscious, say by being hit by the boom, make the auto-inflate PFD my choice, as I don't see dealing with an inflated PFD to be all that difficult.

Posted by: Thomas S | September 7, 2011 1:18 PM    Report this comment

Nothing is perfect, but some PFD objections remind me of people who would not wear a seatbelt because they had heard a story where the auto engine ended up in the front seat in a collision, killing the seat belt wearing driver.
You need to play the odds.
Tethers should keep people out of the water, and once in the water you are better off with a PFD. We wear them 100% of the time, due to all the stories about people being "surprised" they were in the water. Out recent MOB was in 5 knots of wind.

Posted by: WILLIAM G | September 6, 2011 8:51 PM    Report this comment

Force 10 made a substantial foam vest with integrated harness. I bought one about 25 years ago and kept it aboard for rough weather coastal cruising but rarely used it. When I did wear it, there was a feeling of invincibility as it was made so well. The tether was about 8 feet long. Never had an incident with it but liked the pockets, bright yellow exterior coated material and breathable ripstop inner lining. A quick Google search did not locate a similar current product from Force 10. My vest is presently in a consignment shop in Bellingham, WA as I am moving to Florida and the vest would mostly be too hot to wear there. I plan to invest in an offshore quality harness/manual inflate vest.

Posted by: Jim G, S/V Koan 4 | July 31, 2011 1:30 PM    Report this comment

Thanks Kevin, the Hammar hydrostatic inflator used in the Mustang harnesses is pressure activated, so should not inflate from spray. It is more expensive than other inflators to replace, but the replacement interval is longer. Details are in our last harness test -- linked in my post. As I recall, we had a few "spontaneous" inflations during that test, as well. Two of the survivors of the WingNuts tragedy have said that, based on their experiences, they would now opt for manually activated harnesses.

Posted by: Darrell | July 28, 2011 2:19 PM    Report this comment

My two cents - On a recent delivery from Bermuda to Newport, in a time span of about 45 minutes 3 of our expensive auto inflatable PFD's, different brands, inflated. It was a sunny day, a little bit of splash coming over the rail every now and again. Was it accumulated moisture? After they inflated no one wanted to rearm to inflate again and no one wanted to wear the cumbersome orange USCG approve vest. How safe were we then? I'm converting to manual and will consider going hydrostatic in the future.

Posted by: KEVIN F | July 28, 2011 1:55 PM    Report this comment

There is a optional rescue belt that you might be able to offset the ring up front but I would contact Stohlquist to verify.

Posted by: Michael M | July 27, 2011 7:07 PM    Report this comment

Correction on the spelling ( Safety harness )

Posted by: Michael M | July 27, 2011 6:54 PM    Report this comment

Actually a type IV is a throwable device, your thinking of a type V rescue PFD such as the Stohlquist descent I own for extreme whitewater in my drift boat here in Oregon, they would not work with a safty harness since the rescue ring is designed to be on the back of the PFD.

Posted by: Michael M | July 27, 2011 6:49 PM    Report this comment

Thanks Chris. The link for the Whitewater Rescue vest is That looks like it might be worth testing, but would people actually wear it on deck?

Posted by: Darrell | July 27, 2011 4:38 PM    Report this comment

Has anyone tried using Type IV whitewater rescue vests with integrated harness? They can be very low profile and comfortable with quick release harnesses that you can hang a truck off of. In addition, the knife mount is up front and very accessible. Check them out at

Posted by: Chris H | July 27, 2011 4:17 PM    Report this comment

Good questions. I think that a big problem with incorporating a harness into foam PFD would be getting the right fit. A very snug fit is such important part of a harness' effectiveness that the a foam jacket does not lend itself to the design. Most people wear their harnesses too loosely -- thus the current push for incorporating crotch straps or leg straps into harness designs. Personally, I'd rather wear a snug tether without a crotch strap, but many like the added reassurance of a crotch strap. Regardless of what CG might say, I wouldn't try to modify a foam-filled PFD to become a harness because of the fit issues. There are separate harnesses that can be worn under a PFD for adults and for children. If you search under "child tether" you'll see our most recent report.

Posted by: Darrell | July 27, 2011 10:22 AM    Report this comment

There does not appear to be a USCG-approved Type I or II foam pfd incorporating a harness, not even for children. Does my foam pfd lose its USCG approval when I stitch on a harness (from an old inflatable pfd)?

Posted by: ISAIAH L | July 27, 2011 9:54 AM    Report this comment

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