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Old 30-11-2009, 12:31   #31
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"Fun read"? These people must really have a good sense of humor to make getting run over by a freighter a fun read...
They're our next door neighbors. If you knew them (or if you read the book), you'd understand. It's about a lot more than just the mid ocean collision.

Nowhere does it say anything like your "propeller bisected the cat" quote.
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Old 02-12-2009, 11:08   #32
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There are practically NO monohulls out there today, capable of offshore cruising, that are unsinkable. Not that no one has tried. Many have. None have been successful enough to make it commercially viable. None have been successful enough to make it a popular after-market modification. None have been successful enough to even gain any real recognition.

If you can succeed where all the others have failed, more power to you. You could probably write a book about it and make a fortune. I honestly don't wish to offend, but the much more likely outcome is that you will waste a lot of time, effort, and money doing nothing more than duplicating the failures of all of those others.

The choice is yours.
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Old 02-12-2009, 13:02   #33
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the name of the inflatable bags that keep you afloat is from the company called ''float pak'' and if i remember the review spoke very highly of them they are fixed in position in your vessel and if you pull a cord it inflates in seconds and you and your vessel are saved it was advertised in australian yachting magazines hope this helps regards andy
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Old 02-12-2009, 15:13   #34
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I believe the airbag system was called "crewsaver" in the US but i dont think they are still available,i think this is what the Pardeys have on Taleisen,it inflates just like a liferaft. There was a Macgregor 36 cat that put the floatation to the test a few years back in the open ocean. It was on a solo voyage across the atlantic from the US to Europe and was hit by a fishing trawler in the fog while about 500 miles from Ireland,the collision broke off a couple of feet of the bow of one hull,the skipper Hal Andersen was able to fill the hole with sails etc and then continue on unaided.(The trawler lurked in the distance without giving assistance)and without fear of sinking.Ill bet he was thankfull for all that foam.
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Old 02-12-2009, 18:25   #35
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ETAP - Unsinkable Sailing Pleasure

Etap makes a range of monohulls from 21 to 46 feet which are certified unsinkable by the Europeans. I've been on a number of them at boat shows and it's impossible to discern any visible difference between an Etap and similar (sinkable) competitor - they seem to have been rather clever at distributing the insulation throughout the hulls to provide maximum interior space and safety. They also sail very well - the Etap 39 won a number of "Boat of the Year" awards a few years back.

I'm not sure how you would best go about refitting an existing hull but the principle of providing a monohull with positive buoyancy is certainly sound. And Etap have been doing it for 20+ years so it is also commercially viable!
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Old 19-12-2009, 23:14   #36
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So for an update, I got a truckload of large styrofoam blocks delivered to me for $450. I am pretty sure it should have cost around $300-$350, but this way it got done faster (same day). The total volume was 90 cubic feet, but I managed to get a bunch of free styrofoam to give me more than 100 cubic feet. Some pieces are glassed in which is perfect for facing against holes. I am going to give up all standing room except one spot where I can cook (instead of the length of the boat.)

I can manage to live on my boat with all the foam on it before it is even stored, so I think this is going to work fine, and the added insulation is a bonus.

I think most displacement boats could be made unsinkable just because they have so much space in them that is air. If you cut down on area you can move around in, you have just as much (or more storage) as well as all the foam.

I might still get some pour foam to fill the cracks and help "glue" everything together, thought I will not likely need much of it. If there is a leak, I can rip styrofoam out quite easily with my hands to get to it.
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Old 20-12-2009, 01:15   #37
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ETAP - Unsinkable Sailing Pleasure

Etap makes a range of monohulls from 21 to 46 feet which are certified unsinkable by the Europeans.
I remember one of their tests on one of the largest models. Before flooding the boat they did remove some heavy items. Once flooded, the deck was awash with people standing on it, the boat was no more than just a raft. Not every body was impressed.
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Old 20-12-2009, 01:50   #38
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The only boat that is "unsinkable" is the boat that is on the hard.

You really, *really* need to get grounded first with some good education and something to dilute this imaginary idea of carrying foam blocks to prevent you from sinking while you patch a hull underwater, and using that as an alternative to a proper life raft, should there be an emergency of some sort. How much money are you willing to spend to save your life?

If you do none of the above, and hit the water, let's hope that Darwin takes the day off, and please, don't take anyone on your boat with you.
The above is unfortunately a type of post that does very little to assist the creator of the thread, it comes across as patronizing and belittling.
Thanks to all the other posters who least contributed reasonable and courteous debate.
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Old 20-12-2009, 04:30   #39
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Just Googling up Bristol 27 I found displacement 6600 lbs.
6600 lbs = 2993.71 kg = 2.99371 m3 = 105.7219 cubic feet. =/- Adjustment for salt water and weight of foam this does not leave much reserve. Sorry I am metric.
Now displacement is a mysterious figure it is very hard to know what it includes. Designer like to keep it low because the lower it is the more attractive is the design. But it is not uncommon for cruisers to raise the design water line (displacement) by four inches. So unless you flood your boat you will never really know if it will float with the foam installed. To sink is a possibility that every mariner fear and for this reasons many ingenious device have been invented. Until tested no one will knows if they will work.
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Old 20-12-2009, 05:40   #40
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Shaving foam?
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Old 20-12-2009, 07:04   #41
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You are right MarkJ they say that ”brazilian” do not sink.
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Old 20-12-2009, 07:06   #42
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how about explosive keel bolts, a la NASA ,that would just drop the keel as you went down so that one would have a soggy (and sideways )life raft .BTW i am looking for employment as a navel archetect.
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Old 20-12-2009, 19:34   #43
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Just Googling up Bristol 27 I found displacement 6600 lbs.
6600 lbs = 2993.71 kg = 2.99371 m3 = 105.7219 cubic feet. =/- Adjustment for salt water and weight of foam this does not leave much reserve. Sorry I am metric.
Now displacement is a mysterious figure it is very hard to know what it includes. Designer like to keep it low because the lower it is the more attractive is the design. But it is not uncommon for cruisers to raise the design water line (displacement) by four inches. So unless you flood your boat you will never really know if it will float with the foam installed. To sink is a possibility that every mariner fear and for this reasons many ingenious device have been invented. Until tested no one will knows if they will work.
I am not using quite 105cu ft (more like 90-100), but fiberglass is a major component of my boat, and you only need to float 40% of the weight of the glass that is underwater. The wood in the boat also likely weighs several hundred pounds, and it provides positive flotation. Even the volume of the 2500lb balast floats something like 300lbs (so only need 2200 lbs there) I think for this reason it will probably float pretty well, but it is true that I won't know until I try. I will also start throwing heavy stuff overboard like crazy to drop another 600lbs of sinking stuff if needed. Anything onboaard that floats, I might as well keep it.

I plan to get an epirb so if the boat sinks, I will have it on an inflatable (not a proper life raft though)

I found that I can only cut the styrofoam (using stainless steel wire from my lifeline across 12v battery) to fill 80-90% of the void. It is just too hard to cut the pieces to fit perfectly especially around rounded edges. For this reason I think unfortunately I will be purchasing a small amount of 2 part pour foam to fill the gaps. Hopefully I can fill most of the space this way.

I did not want to get the pour foam because at only 50 degrees it only expands to about 50% of the 80 degree volume. It was also about
twice the expense (4 times at 50 degree weather) I think I will pour it when I get farther south. It will also give me additional flotation margin.

Thanks for all the replies
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Old 22-12-2009, 08:21   #44
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Even the volume of the 2500lb balast floats something like 300lbs (so only need 2200 lbs there)
Because this volume is submerged (below the water line) it all ready contribute to the flotation of the craft.
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Old 22-12-2009, 09:02   #45
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Do a small test with that two part foam on the Styrofoam...it will probably melt the Styrofoam.
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