Would a mac sink like this?

[williamtl]

An unfortunate sailing family had their boat sink. See the "My boat sank today" Discussion in 'Ask All Sailors' started by stiggy456, Oct 1, 2015.

My question to the Mac 26 owners and former owners is Would the Mac 26 sink like this or would the floatation keep it from sinking? My assumption is that it would be floating with the deck barely above or just below the surface.

The bonus question is, Would it make any real difference? It seems to me that everything on the inside is going to be just as wet. It may cost less to salvage as you won't have to get it to the surface, "just" pump it out.

And yes, I'm still considering reclaiming all of the space currently used by the floatation.

 

[willsnow]

Sink like that? No way. Their rudder stock came loose and dropped the rudder while on the mooring. And even all the previous talk on that thread about seacocks is not applicable to our boats. We (water ballasted Mac Classics) have 2 "through-hulls" that are above the water line for the sink drain and the cockpit drain. The only way ours could sink is catastrophic damage to the hull (above the ballast tank) or - more likely, the ballast tank valve itself could allow water in, if used improperly or it breaks.
And as to the flotation foam, skip to 27:30 in this 25 year old introduction video:

Now, I haven't actually removed any of the foam in mine yet... but I think all the extra stuff (batteries, fresh water tanks) on board may over power the foam that came from the factory

 

[anthony]

We had a bad storm last year, "Nanna" was rocking and rolling with the waves at the dock.
Well to make a long story short, the cockpit drain let go and Nanna started to take on water.
The water was up to the cushions in the cabin, they were floating. I put a bung in the through hull, the motor was still on the back of the boat and there were three of us in the boat with pumps, still no sign of it sinking, I would hazard a guess and say she would have floated up to the gunwales Oh yes all flotation in place..

 

[JuneF]

How much foam is supposed to be the boat. I recently purchased a 93 26S and there are only 3-4 pieces of the grey foam in the boat. This doesn't seem like much. Thanks

 

[williamtl]

JuneF,

Some of the flotation in my '95 26D is in compartments that are sealed so I can't see it all of it. There is supposedly some under the cockpit seats, some over the sink, and some where the anchor locker should be. Note that at some time in the past, charcoal lexan was put over holes cut into the location over the sink and anchor locker. What I can see in those two areas looks like the white styrofoam (at least I think that's what it is) that is commonly used around electronics when they are packaged.

My guess as to how much is above the sink: 6" deep x 18" x 30". Where the anchor locker should be: 6" deep x (1/2 * 18" * 24"). Ok, I know the anchor locker is not a right triangle, but these are all guesses anyway so should be close enough.

 

[williamtl]

My latest thought on this is a crazy one. You could easily calculate the volume of the current material (by taking it out ) and then calculate the amount of flotation it would provide.

Given this information, could you calculate the amount of spray foam insulation that you would need. Then, put garbage bags where the top and bottom come together and spray the foam insulation into the bags. See the blue arrows in the picture for where I am talking about. This slot runs from bow to stern on my 26D. Note that I'm sure there is a nautical term for "this slot" so folks can feel free to educate me on what it is.

You could replace the amount of flotation (or probably even increase it) however, it would be in different places than the original, but still near the top of the boat. It would be in a place that is totally unusable at this point (except for running wires so you may want to put in pvc conduit with a pull string or two for future use.).

As I started out, this is a crazy idea. You may have noticed, I really want an anchor locker and the space under the cockpit seats would be really great as well.

Thoughts?

 

[Macboy]

Whenever I hear talk about the positive flotation foam I can't help but think of the myth busters episode where they used ping pong balls to raise a sunken boat. Can't recall if their plan worked out. Guess I'll hit YouTube after I post this reply.

If you could determine the volume required then couldn't a person make up some sort of airbag system that deployed like those auto inflate PFDs if the situation ever arose? Surely such a thing already exists? It wouldn't even have to be internally installed really. It could be an on-deck sort of thing.

I recall a friend's dad installing a ballistic parachute contraption on his ultralight to ease the wife's fears. Ditto here. You can bet your bottom dollar I explained the unsinkable nature of the Mac to my wife when we bought it. Even watched the promo video with her.

 

[Jackdaw]

Do people REALLY think about a boat sinking to the point where they worry about it? To me that's kind of like looking for a house that is safe from fire. In the big picture, boat sinkings are so very rare.

Just like the house, take sound precautions. Then go sail.

 

[Macboy]

I know it was certainly something that was on my wife's mind. Nice to have been able to show her the clip from the video. But you're right - all precautions are taken and the boat is used responsibly and respectfully. But still.......

 

[Apex]

Whenever I hear talk about the positive flotation foam I can't help but think of the myth busters episode where they used ping pong balls to raise a sunken boat....
.

THanks for the prompt to watch those episodes: haven't watched that show in a while so good to see. What was even more interesting was their ping pong ball insertion method! Who'da thunk Walt would be so accurate?????

 

[Jackdaw]

I know it was certainly something that was on my wife's mind. Nice to have been able to show her the clip from the video. But you're right - all precautions are taken and the boat is used responsibly and respectfully. But still.......

Good enough for me!

 

[Leeward Rail]

Do people REALLY think about a boat sinking to the point where they worry about it? To me that's kind of like looking for a house that is safe from fire. In the big picture, boat sinkings are so very rare.

Just like the house, take sound precautions. Then go sail.

Totally agree. That's why they make radios with VHF chan 16, life jackets, life rafts, and have a coastguard.
So the boat goes down and floats with the deck at the waterline due to flotation ? Time to worry about hypothermia...

I don't worry that my house will burn down, that I'll get robbed, that I'll get in a car accident, that my plane will crash.
As long as we use our brains and be responsible, worrying is unproductive and pointless.
For sailing, as long as you are not negligent on board, the biggest risk is probably driving to the marina.
Fears are from unfamiliarity. Best solution is make sure that you and your crew are skilled, and therefore confident.