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Old 22-12-2009, 20:54   #46
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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.
The EU directive is that there needs to be freeboard (about a foot as I recall) and the boat must be sailable. You can read the PBO Etap tests and see that the decks were well clear of the waterline. And that the boat could be sailed.

The unsinkable Etap 46DS won the European Boat of the Year.

And ultimately it didn't sink, did it?



I actually think the OP is onto something - if it is possible to make monohulls that don't want to sink (and it demonstrably is) why isn't this feature more prevalent in the market? It doesn't have to be foam - it could be achieved with watertight bulkheads or storage spaces.

I suspect these would all add to the base price in a marketplace where the lowest base price is the object. And they're not exactly something that can be retrofitted as a high profit option (like bug screens for portlights and hatches ha, ha, ha).
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Old 23-12-2009, 20:32   #47
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why isn't this feature more prevalent in the market?
How great is the risk of sinking?
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achieved with watertight bulkheads or storage spaces.
Many productions and racing boats are equipped with watertight bulkheads or storage spaces and so was the Titanic.
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Old 23-12-2009, 20:46   #48
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How great is the risk of sinking?
It is significant enough that people carry liferafts...

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Many productions and racing boats are equipped with watertight bulkheads or storage spaces and so was the Titanic.
The Titanic sank because she didn't have watertight compartments - the bulkheads ended below the decks and were flooded over the top. One after another and she sank.

Personally, I like hard to sink boats.
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Old 23-12-2009, 20:48   #49
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Not totally true

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How great is the risk of sinking?

Many productions and racing boats are equipped with watertight bulkheads or storage spaces and so was the Titanic.
Titanic's Bulkheads & Watertight Compartments
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Old 23-12-2009, 22:46   #50
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It is significant enough that people carry liferafts...
The fear not the risk motivates people.
The Titanic was deemed to be unsinkable.
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Old 23-12-2009, 22:53   #51
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The fear not the risk motivates people.
The Titanic was deemed to be unsinkable.
Because it was marketed as such.
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Old 23-12-2009, 23:27   #52
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From what I can see the bulkheads are well above the water line, proper calculations would have been made. A lot has been written on the Titanic even to claim that had the captain not activated the doors more people’s lives would have been saved. The fact is that the Titanic sank.
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Old 23-12-2009, 23:42   #53
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Reminds me of a favorite quote:

"Don’t be afraid to try something new, amateurs built Noah’s Ark, professionals built the Titanic"
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Old 17-01-2014, 21:51   #54
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Re: Where to Get Foam to Make Boat Unsinkable

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I am interested in making my boat unsinkable, so incase it gets punctured I wont sink and can hopefully repair the leak (underwater epoxy) then bail out and keep going. , I calculated I need 100 cubic feet of flotation.

I took some measurements, and I found I have space for 45 cubic feet under the bunks, I have not counted underneath the cockpit which I imagine has another 45 cubic feet. I am close enough that I may just have to put additional flotation higher up to reach enough.

I can also throw 500lbs overboard in this event if needed. o Some additional flotation may be in the form of 5 gallon buckets or other sealed containers which can be used for other purposes normally.

I am wondering where I can get the foam to do this. I am not sure what to look for, but something that sprays in place would be nice, but I wouldn't mind cutting blocks to fit if I had to.

I appreciate any comments or insights into this task, Thanks.
I HAVE the same worries and you are right about do not loose the boat in any circunstances, but i think you could contemplate making emergency bags similar to the ones installed on cars, but bigger and custom made and mouted on the bunks, on the roof, obviously made to fit spaces and to expulse water activated by a CO2 or Nitrogen High pressure cylinder wit an integrated stailless steel or enginnering plastic maniful to support 2000 pounds per square inch, operated from the cocpit, making sure there is no persons down.
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Old 17-01-2014, 22:01   #55
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Re: Where to Get Foam to Make Boat Unsinkable

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I HAVE the same worries and you are right about do not loose the boat in any circunstances, but i think you could contemplate making emergency bags similar to the ones installed on cars, but bigger and custom made and mouted on the bunks, on the roof, obviously made to fit spaces and to expulse water, activated by a CO2 or Nitrogen High pressure cylinder with an integrated stainlless steel or enginnering plastic maniful to support 2000 pounds per square inch, operated from the cocpit, making sure there is no persons down.
I also put solar cells and a communications radio with batteries embedded on the roof to make it work on any circunstances.
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Old 18-01-2014, 02:05   #56
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Re: Where to Get Foam to Make Boat Unsinkable

How about some exploding keel bolts... if you jettison that pesky heavy keel I bet your foam filled boat would float pretty good.

Maybe a catamaran... apparently some will float even filled with water.
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Old 18-01-2014, 03:01   #57
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Re: Where to Get Foam to Make Boat Unsinkable

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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.

Actually it's you who needs to get the good education. There are plenty of boats that are unsinkable. Just about every trailerable powerboat is unsinkable. In fact in most countries it's a legal requirement to have at least basic floatation even if the boat is flooded or holed.

A boat that doesn't carry ballast is actually quite easy to make unsinkable. It's the several tonnes of lead keelboats carry that makes it difficult. But not impossible. The ETAP range of keelboats is unsinkable.

A friend of mine designed and built his own keelboat with positive buoyancy. It does take up a lot of potential storage space, but it saved his boat once. A good trade off he feels.
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Old 18-01-2014, 04:15   #58
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Re: Where to Get Foam to Make Boat Unsinkable

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The only boat that is "unsinkable" is the boat that is on the hard.
My buddy was kidding me the other week. Ours has been slowly sinking on the hard - Down at least 6 inches at the stern. We are going to have to dig a pit and jack it back up and re-block it!

BTW, a few years back there was a company who sold custom flotation sleeves for just such a problem. In an emergency you pulled a pin and they would inflate. Very pricey as I recall.
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Old 18-01-2014, 04:19   #59
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Re: Where to Get Foam to Make Boat Unsinkable

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Originally Posted by 44'cruisingcat View Post
Actually it's you who needs to get the good education. There are plenty of boats that are unsinkable. Just about every trailerable powerboat is unsinkable. In fact in most countries it's a legal requirement to have at least basic floatation even if the boat is flooded or holed.

A boat that doesn't carry ballast is actually quite easy to make unsinkable. It's the several tonnes of lead keelboats carry that makes it difficult. But not impossible. The ETAP range of keelboats is unsinkable.

A friend of mine designed and built his own keelboat with positive buoyancy. It does take up a lot of potential storage space, but it saved his boat once. A good trade off he feels.
Bazinga. You got him. Mind you, in the four years since his post he may have got a bachelor's degree.
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Old 18-01-2014, 04:48   #60
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Re: Where to Get Foam to Make Boat Unsinkable

Greetings and welcome aboard the CF, Joe Gascon.
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