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Old 15-04-2012, 05:54   #1
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Hydrostatic release or not?

What are the pros and cons of hydrostatic release on your liferaft?

Some of the fit ups I've seen don't look like they'd survive a savage knockdown or a brutal wave dumped on top of them, which is just the situation when you might need it.

How is yours secured?
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Old 15-04-2012, 06:34   #2
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Re: Hydrostatic release or not?

Fastened into it's cradle with webbing and over-centre clips, the levers of which have a slot over a tab with a hole for a spring clip to prevent accidental release.
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Old 15-04-2012, 06:35   #3
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Re: Hydrostatic release or not?

I have one fitted, Hammar H20. Needs about 4 meters head of water to activate. Have mine situated aft of the life raft so that the cannister protects the unit from water coming over the deck.
Used them for the past two years, not activated yet
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Old 15-04-2012, 10:39   #4
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Re: Hydrostatic release or not?

The device (hammar type) is designed the way a passing wave or a boat roll will not release.

My only worry would be if you get run down in less than 4 meters of water ...

;-)

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Old 15-04-2012, 11:17   #5
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Re: Hydrostatic release or not?

A proper hydrostatic release will not release from wave action. As others have said, it requires a specific amount of pressure to release.
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Old 15-04-2012, 12:37   #6
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Re: Hydrostatic release or not?

The very biggest, most important issue in cruising/sailing is to keep things SIMPLE. If anyone is happy to flop around treading water in mid-ocean till their boat gets to 4m depth and then hope that their hydro release is actually going to work and the raft is not getting hooked up on something,(halyards/sheets/spinaker poles) down there, good luck. Me, I'd rather deploy my raft myself. While we're on the subject, a far better bet is an unsinkable hard dinghy with mast, sails and a grab bag lashed inside. Ships carry lifeBOATS and so should yachts. A liferaft is an expensive to buy and expensive to maintain inflatable boat and we all know what rubbish an inflatable is.! Rather than bob around out there trying to keep an inflatable inflated, step a mast and sail home. !
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Old 15-04-2012, 12:44   #7
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Re: Hydrostatic release or not?

They work. A couple sailing to SF from Hawaii went missing. Their hydrostatic released epirb and life rafts were found floating around with some debris from the boat. Unfortunately, the couple weren't found.

They might be a lifesaver if you get run down by a ship or other instant sinking situation but those are very rare. I'd rather pull the string myself, however.
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Old 15-04-2012, 13:06   #8
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Re: Hydrostatic release or not?

"A proper hydrostatic release will not release from wave action. As others have said, it requires a specific amount of pressure to release. "

But what clever design tells the release "we're submerged" as opposed to "a six meter wave just broke over the bow and dropped on us" ?

Considering the impact generated by simple "dropping" water, which requires substantial strength in hatches and other construction, if something capable of smashing thin glazing splashes onto a hydrostatic release, isn't it going to trip that release?
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Old 15-04-2012, 13:21   #9
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Re: Hydrostatic release or not?

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Originally Posted by holmek View Post
A liferaft is an expensive to buy and expensive to maintain inflatable boat and we all know what rubbish an inflatable is.! Rather than bob around out there trying to keep an inflatable inflated, step a mast and sail home. !
You'll find quite of lot of newer built ships do not carry lifeboats, but an excess of liferafts. In the long term on a ship, rafts are cheaper.

As to a hydrostatic release on a raft on a yacht, I'm happy to have the choice, if need be, I can release it myself, if I get run down in the middle of the night, I hope that it will release it self. Dont think anyone with a hydrostatic release fitted is going to wait for it to activate if they have the choice to manually release
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Old 15-04-2012, 13:50   #10
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Re: Hydrostatic release or not?

Yes, of course Nigel1, There would be the choice of manual or hydro, I hadn't thought that through. But I will still stick with a hard dinghy!
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Old 15-04-2012, 16:42   #11
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Re: Hydrostatic release or not?

A hard dinghy in big storm seas is not going to be much good. Add that it is not covered and the prospect of it saving your life is not great. Good liferafts are designed to stay upright in almost any sea and provide some protection from the elements. I knew one guy who spent 31 days in a liferaft after sinking off Cape Hatteras about 25 years ago. He was picked up off Exuma after the 31 days. Open exposure for that period of time, sun and wind, he would not ahve survived.
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Old 24-04-2012, 11:56   #12
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Re: Hydrostatic release or not?

Like any piece of safety equipment, hydrostatic releases (HRU) are not an "install and forget it" piece of equipment. The most common model, the Hammar H-20 has a two (2) year service life and is a disposable device (replace it, you can't have it tested). Fitting a HRU still allows one to manually release the raft which should always be your primary means of launching the raft. The biggest difficulty I have seen with HRU's is improper installation. Check out Hammar's site for more information.
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Old 24-04-2012, 21:49   #13
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Quote:
Originally Posted by holmek
The very biggest, most important issue in cruising/sailing is to keep things SIMPLE. If anyone is happy to flop around treading water in mid-ocean till their boat gets to 4m depth and then hope that their hydro release is actually going to work and the raft is not getting hooked up on something,(halyards/sheets/spinaker poles) down there, good luck. Me, I'd rather deploy my raft myself. While we're on the subject, a far better bet is an unsinkable hard dinghy with mast, sails and a grab bag lashed inside. Ships carry lifeBOATS and so should yachts. A liferaft is an expensive to buy and expensive to maintain inflatable boat and we all know what rubbish an inflatable is.! Rather than bob around out there trying to keep an inflatable inflated, step a mast and sail home. !
This is not good advice. Small rigid dinghies that are capable of being carried on a typical yacht DO NOT provide a survival environment. Firstly they are easily swamped. Secondly they provide little or no protection from the environment and thirdly they are easily overloaded by a typical yacht crew. The chances of survival in open water in such a device are minimal.

Contrast this to a proper liferaft . It provide excess buoyancy capable of supporting 4,6 people with ease. It has a insulated double bottom for safety , protection from cold etc. it has drogues and water ballast pockets to aid survival in poor conditions. It's offers shelter from the elements.

The average time these days in a liferaft in 4 days. There's no need to sail anywhere. You stay put , keep alive and help comes. That's the safety philosophy under GMDSS.

By the way lots of passangers ferries and ships carry liferafts not lifeboats. Fast ferries etc are almost exclusively liferafts. ( usually 20-40 man)

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Old 24-04-2012, 23:10   #14
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Re: Hydrostatic release or not?

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Originally Posted by Eleebana View Post
What are the pros and cons of hydrostatic release on your liferaft?

Some of the fit ups I've seen don't look like they'd survive a savage knockdown or a brutal wave dumped on top of them, which is just the situation when you might need it.

How is yours secured?
All reasonable replies which indicates there is no one best answer. Hydrostatic releases give more options but also potentially more problems.

As to how and where to stow the raft, I believe it depends mostly on the boat. Smaller boats give less options!

I can only give my experience on 30 footers. I used to mount it on the cabin top forward of the companionway.
No problems until we were knocked down one day followed by large(ish) wave washing over the boat and taking the raft out of it's chocks and lashings. It ended up on the deck against the lifelines. Took some effort to get it back to where it should have been. Conditions weren't good or that bad, probably 3 metre swells with a 2 metre sea running and 25 to 30 kts of breeze with gusts perhaps 35 Kts. Lashing and chocks were as supplied by the raft manufacturer. BTW, we were tethered in the cockpit at the time hand steering (and looking concerned)!

These days I don't have a raft but will hire one for long off-shore passages if such are undertaken. I plan to stow in the cockpit (aft end) under the tiller secured with my own strongpoints and lashings with knife permanently stowed nearby.

BTW, I have never personally like stowing the raft below but others have.
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Old 24-04-2012, 23:29   #15
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Re: Hydrostatic release or not?

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Originally Posted by goboatingnow View Post
This is not good advice. Small rigid dinghies that are capable of being carried on a typical yacht DO NOT provide a survival environment. Firstly they are easily swamped. Secondly they provide little or no protection from the environment and thirdly they are easily overloaded by a typical yacht crew. The chances of survival in open water in such a device are minimal.

Contrast this to a proper liferaft . It provide excess buoyancy capable of supporting 4,6 people with ease. It has a insulated double bottom for safety , protection from cold etc. it has drogues and water ballast pockets to aid survival in poor conditions. It's offers shelter from the elements.

The average time these days in a liferaft in 4 days. There's no need to sail anywhere. You stay put , keep alive and help comes. That's the safety philosophy under GMDSS.

By the way lots of passangers ferries and ships carry liferafts not lifeboats. Fast ferries etc are almost exclusively liferafts. ( usually 20-40 man)

Dave
and a hard dink did not help us get to shore in lake superior in june...
Average time to dead in 34 degree water is?
every problem is different.hard dink was a solution to ours.
your milage may vary
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