23.5 unsinkable???

[massnspace]

Have been noticing small amounts of foam in my Hunter 23.5 sailboat while working on systems. Small amounts.

Heard somewhere that the boat is “unsinkable”. Is this true? Is there any actual evidence (photo, etc), to prove this?

We sail where the water is about 49 degrees F year round. Would be nice to know.

David
Seattle

 

[Crazy Dave Condon]

@massnspace

I was a hunter dealer who gave the original plans for the 23.5 to Hunter and was involved with the design of all water ballast sailboats. One of my criteria was to include positive flotation so the boats to include the 23.5 would not sink. Thus the foam flotation you see in your boat

Crazy Dave

 

[massnspace]

Again.

I am asking if this has ever been verified in any way. Tested? Any link to a news story of one actually being holed and floated back into port?

Seems like a very minimal amount of foam in the boat to me….

Thank you

Sane David
Seattle

 

[Crazy Dave Condon]

The 23.5 was tested in the Hunter pond with me there @massnspace Just ask who I am Enough said

 

[massnspace]

Pics of that test? (I am sure someone there would have taken a lot of pics…)

Was an engine on it? Tanks empty or full? Several people on board? Anchor and chain? Mast and rigging?

 

[Crazy Dave Condon]

It has been 35 years ago when that was done with weight added to include the sales rep and myself. Cannot remember all them thar details, so if you want more specifics, I guess you will need to look elsewhere for answers as I have answered your question

 

[CrispyCringle]

The last thing Id worry about is a 23.5 sinking. But if I was in salt water I wouldn't take it far at all from shore either. To tender for any serious wave action for extended periods. At least for me.

 

[rgranger]

First off... @Crazy Dave Condon is da man when it comes to the H23.5, H26 and H260 and has helped many of us (myself included) with setting up our boats, and trouble shooting issues. If he said he tested it... it was tested.

Second off... The ballast in the H23.5 is water. So the foam only has to off-set the extra density of the fiberglass (only slightly higher than water) and the rigging & gear etc.

 

[JBP-PA]

You should check the condition of the foam. Older foam can deteriorate and even become water logged to the point it no longer provides flotation.

 

[Crazy Dave Condon]

@JBP-PA is correct which should always be considered. Thank you sir

 

[massnspace]

The foam in my boat is in excellent condition. Not degraded or waterlogged.

But I am not believing the boat is unsinkable. I have been around the entire boat multiple times now and there are very minimal amounts of foam here and there. Unless the entire hull is foam cored (double-hull with foam between the skins) I am just not believing it. The boat weighs 2000 lbs. Add the motor, gear, 2 people aboard, etc. etc and that adds another 500-700 lbs. Where are all the cubic inches of foam hiding in the boat that would float 2,700 lbs.?

Show me some pics of it floating when holed and I will apologize. Otherwise, I will assume it sinks and continue to research options for our safety.

David
Seattle

 

[rgranger]

A 2000 lb tree floats....

 

[massnspace]

2000 lbs. of closed cell foam floats, too. As does 2000 lbs. of air.

2000 lbs of solid fiberglass sinks….a 100 lb metal outboard sinks. An aluminum mast and boom also sinks. Anchor and chain sinks.

Show me a picture of one floating after being holed and I will apologize.

Attached are pics of floating, flooded boats. But I know each of them has a LOT of foam between the 2 hull skins. The entire hull is foam-cored on these boats. The Hunters are SOLID GLASS. Apples and (foam-filled) oranges.

 

[Davidasailor26]

I will assume it sinks and continue to research options for our safety

Crazy Dave saw it float and that would be good enough for me to say it’s possible. But in any case I would not call a floating flooded boat a “safe” situation. Keeping the water out seems a prudent safety measure for any boat. If it stays afloat that’s just a small risk mitigation.

 

[CrispyCringle]

Im not sure what the fixation is on an unsinkable sailboat. But everyone has their own list of personal preferences that need to be checked. "Your boat, your rules", as they say. I do hope you let us know what you decide on when you make your decision. Ive only heard of a few sailing boats that market "unsinkability" as a design feature. Maybe not even marketed, but simply mention, and imply, a water tight bulkhead or locker. Mostly in large sailboats where a chain locker or a sealable bulkhead door is actually made for the job of keeping at least one end of the boat floating. The Amel Super Maramu comes to mind. Its a 53 footer with fore and aft sealable bulkhead doors. I think it may have been tested, but wouldn't guarantee it. And Boston Whalers were at one time marketed as unsinkable, but not sure if they still do that. But I think it would be a serious liability issue to make a claim of "unsinkable". Someone will always find a way.

 

[rgranger]

(snip)...Ive only heard of a few sailing boats that market "unsinkability" as a design feature......(snip) Someone will always find a way.

This boat was marketed as unsinkable...

 

[shemandr]

I can tell you for a fact that a popular well regarded 80' - 90's, 28' boat will go straight to the bottom unbelievable fast. All that was necessary was a lazartte that opened in a knockdown. Water flooded into the cabin (Because there is no watertight bulkhead) and the boat was headed to the bottom in under 30 seconds. Thankfully everyone got out but if someone were below in a berth they wouldn't have a chance.
I think Etap's have enough floatation to not sink..
I think it would be entirely possible to have a bladder around the boat, like an inflatable, that can inflate and provide floatation enough to keep the boat afloat. But I don't think few squirts of foam will do it if you have a keel.

 

[rgranger]

. But I don't think few squirts of foam will do it if you have a keel.

The H23.5 is water ballast

 

[Johann]

The H23.5 is water ballast

Yes, and also there’s quite a bit of foam in the cockpit coamings and in the sealed area under the v berth. And while the glass fiber is more dense than water, the resin is close to the same density as water, and is present at about a ratio of 2.5x the glass fiber. So 2000# of fiberglass doesn’t require 2000# of floation.

 

[dlochner]

The issue is not weight, it is displacement and density. This is best illustrated with a PFD example. An adult sized PFD has about 22 lbs of flotation but will keep a 200 lb person afloat. Why? Because it is the relationship between the volume of the object being floated, its weight and the weight of a similar volume of water. This is displacement. When the weight of an object is greater than the weight of a similar volume of water, it will sink. If the weight is less, it will float.

To make a boat unsinkable (which usually means the gunwales will be above water when the boat is filled with water) enough foam has to be added to offset the weight of the boat over the weight of the same volume of water. That is pretty easy to accomplish.

Here's an experiment to demonstrate this that you can do in your kitchen sink. Take an aluminum can of beer and an aluminum can of soda and place them in a kitchen sink. The beer can will float and the soda can will sink. The beer floats because 12 oz of beer weighs less than 12 oz of water because alcohol weighs less than water. Soda weighs the same as water and the added weight of the aluminum can causes it to sink. The alcohol in the beer reduces the volume of water in the can making it lighter than water and sufficiently lighter than the same volume of water and the weight of the can.

Here's another thought. A person who weighs 200 lbs on land requires less than 22 lbs of floatation because most of our body is made of water and fat, thus the fat floats itself and the water weight does not need to be floated. The 22 lbs of floatation only has to support the weight of out bones and teeth and the clothing we are wearing.

This is the basic principle of displacement. A concept ancient Greek philosopher Archimedes discovered in his bathtub (or so the story goes). If this explanation isn't clear, spend some time reading about displacement, I have no doubt there are better explanations out there.

The upshot is, it doesn't take much foam to float a 2K lbs boat and there is lots of room between the hull and the liner for that foam.