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LuckyinLA 08-19-2004 08:47 AM

SOSpenders autoinflate in rain?
I have the auto-inflate version of the SOSpenders pfd When I bought it, a guy behind me in the shop said "watch that thing in the rain..." Well, this has me wondering, if it will auto-inflate itself while I''m wearing it. Likely it is in bad weather that it will definately be worn. Has anyone experienced a surprise auto-inflate? TIA

Jeff_H 08-19-2004 08:55 AM

SOSpenders autoinflate in rain?
I have worn an older SOS self inflator harness for roughly 10 years now in a range of conditions and it has never inflated. I have heard of self-inflating vests inflating in bad weather but I have not esperienced it. I recently replaced my old one with one of the new SOS units that is made to only inflate when actually underwater.


fer@fer 08-23-2004 06:34 PM

SOSpenders autoinflate in rain?

The guy behind you in the shop is right.

Just watch that thing during the rain, and after it.

As far as I am informed, there are two Automatic inflation mechanisms.

The one used by Sospenders, which consists of a salt bobin that when in contact with water (or humidity) dissolves itself, and triggers the mechanism which actuates on the Co2 cilinder inflating the pfd. This salt bobin, has a one year life expectancy. But when the pfd has been used in heavy seas or rain for a long period (long period in my experience is more than 8 hours), and you find the thing wet as your gloves, you can expect it to autoinflate any time at all.

After having such experience a couple of times, After 4 or 5 hours I instruct the crew to desarm the bobin, and store it inside.

Crew must also pay attention to carefully assure that the velcro closing system which enclosures the red pull tab, is securely fasten. Crew rushing on deck may accidentally open the velcro and let the red tab get caught in any piece of equipment, (a cord, block, or whatever), and manually inflate the thing as well. Last time happened to me with the wheel steering, in a 50 knt blow. I assure you that with that thing inflated on board, you are a handicapped, unless you are able to take it off.

After rain stopped, you must check thet the pfd are desarmed, and the bobin stored in a dry bag. SHould you live the pfd armed, humid, they will autoinflate, hours or days after, but they will do. My concern has been always wether those bobins exposed to high humidity where still in good service. I will tell you, that I''m not going to do the test. I just don''t use them any more.

The other automatic system, consists of a mechanism known as Hammar hydrostatic,
which actuates under water pressure.

You can find additional info on this

or googleing "hammar".

This mechnism is used by the Crewsaver pfd.

By the time I found this tech notes, I had already bought 8 sospenders and its replacements kits. So, since they all have a built in arness, we no longer use them with the bobin.



Oscar 09-12-2004 03:47 PM

SOSpenders autoinflate in rain?
I had the salt bobin slowly deteriorate and the SOSpender auto inflated while hanging on a hook in the head....scared the sh&t out of the admiral, and I was glad I wasn''t in it. Got a replacement kit and broke the very fragile little "pin" that holds the manual inflate handel in place. If I was a conspiracy thinker I''d say it''s all designed to promote the sale of 30+ dollar kits......Still, it''s better than a bulky type II or I.

Oscar and family
"Lady Kay" C-42 # 76 10-08-2004 07:31 PM

SOSpenders autoinflate in rain?
Everyone is right, to some degree. I have used my SOSpenders equivalent on and off. Just be very careful to always ensure the SOSpenders (or any other autoinflatable) is the LAST LAYER to be put on, and the first to be taken off. Long story short (not mine, but in the Hobart disaster race) you don''t want it to inflate under a restrictive jacket. It can crush your rib cage.

I had mine on in a blinding rain stornm, visbility less than 100 yards. No problem. Two days later while bending over, it inflated automatically and I didn''t know what it was for the first 2 seconds and I darn near had to change my pants. The regimen I use now is I use it in manual inflation mode, unless it looks like nasty weather, and then I reArm it for automatic. Most accidents I read about where people are lost is either no PFD or they were knocked unconscious and overboard. (yeah, harness, but that''s another topic).

I have found by shopping carefully both the "Bobbins" and the "CO2" bottles can be purchased separately and much more cheaply than the "kit". One Caution. The Date marked on the "bobbin" is one year before the expiration date, and many stores put them on SALE just before they expire. The included instructions explain both the Dating of the bobbins, and the periodic inspections which should be done (mea culpa). Some people learn the hard way! (Who me?) BTW - Don''t expect all chandleries to have knowledgable staff or that they all know the difference. I have a passion for opening stuff and reading before I buy it.


WHOOSH 10-20-2004 01:46 AM

SOSpenders autoinflate in rain?
Bob, I think your comments are an excellent summary of what can be expected and what one should do re: maintenance.

Most boat systems rarely get attention unless performance becomes flaky OR the financial consequences of ignoring the maintenance loom large. This is doubly true of personal safety equipment, which we almost never ''use'', even tho'' we benefit continuously from its presence. All of us tend to overlook the simple truth that an annual inspection and, at the least, bobbin replacement on each of our inflatable harnesses - even if things look OK - is no less important than other critical maintenance items which get that annual attention.


miyagi 11-23-2005 05:25 AM

SOSpenders autoinflate in rain?
We use auto inflate PFDs in our armed shipboarding/drug interdiction duties and in five years have not had a problem. As pointed out tho regular maintenance is needed.

Irwin32 11-23-2005 02:22 PM

SOSpenders autoinflate in rain?
Stuff happens. Everything has its good side and bad side. I elected to go with a manual, but that is not foolproof either. I single hand a lot and wear my inflatable when I do. I usually do not tether on when in the cockpit. When tethered on deck, I have found it easier to disconnect the tether at the vest when I return to the cockpit, leaving the tether hanging over the combing and still attached to the jack line. Last summer I finished my deck work and came back into the cockpit. I was looking at the sails to see the results of my efforts as I disconnected my tether - I pulled the wrong lanyard....
Time to rearm the vest. Boy, was I surprised!

marinedtcomRob 11-29-2005 01:15 AM

SOSpenders autoinflate in rain?
We''ve sold the SOSpenders line for about five years now and in all the customers I''ve spoken with I can only remember one instance of the jacket inflating pre-maturely due to being in a very moist environment. So while I guess it can happen, I wouldn''t lose any sleep over it. Carry a backup re-arm kit and replace the bobbins each year as recommended if you want to be on the safe side. Presently Sailnet carries the Mustang Survival vests and they are releasing, in the next week or so, a new model for 2006 called Mustang Survival Auto Hydrostatic Inflatable PFD model MD3183 which is designed for extreme conditions and no longer uses a bobbin to trigger inflation.


PS - BWT someone above mentions $30 rearm kits for Sospenders. Sailnet still carries these and they''re a LOT less than $30. See: rm&x=0&y=0

(do a search for "sospenders rearm")

WHOOSH 11-29-2005 03:12 AM

SOSpenders autoinflate in rain?
I''m surprised a bit by Rob''s comment since just our two SOSpenders vest/harnesses have self-inflated multiple times. I think you can look at these units from two perspectives: for heavy users (we are full-time cruisers who do occasional long offshore legs, when we wear the harness vests almost 24/7), the bobbins'' internal tablets simply dissolve more quickly over time (humidity, soaking rain, on-deck spray) and annual bobbin replacement is good practice. For daysailing/seasonal users, the bobbins simply are exposed far less to wet/humid conditions and so the tablets survive longer.

I''m not sure which was more ''fun'': sitting quietly in the cockpit and reading when the vest suddenly *exploded* into inflation next to me...or wearing it when it happened.<g>


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