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Posted: Mon Mar 31, 2008 8:29 am
by parrothead
Did he remove flotation to create room for water storage.... The bladder is forward of the storage area where the air escape vent is for the ballast.
Just this weekend, I ran a hose through that compartment in my :macm: to tie a passive ballast tank vent into the thru-hull that drains the anchor locker --- and I can assure you that nothing can possibly be added to the space under the front of the V-berth without removing styrofoam.

Posted: Mon Mar 31, 2008 9:18 am
by Russ
Trouts Dream wrote:Extra flotation could be had by placing a few extra auto-inflation life jackets in strategic locations.
:) Money is no object
Or just fill all those empty spaces with ping pong balls. I saw that done on Mythbusters to raise a sunken boat.

On a serious note, I wonder how much "spare" flotation is built into a Mac?
The extra weight of a 70hp motor, extra anchors and gear, would a heavily loaded Mac put it over the flotation installed? Would removing a couple of feet to store an which handle or make a cup holder really make that much of a dent?

Posted: Mon Mar 31, 2008 9:46 am
by NiceAft
Cat,

It's a 30 gallon bladder.

Briefly, I was thinking of some sort of pumped in foam insulation. If it's a matter of Styrofoam, I have access to plenty of blocks of that stuff.

Ray

Posted: Mon Mar 31, 2008 11:24 am
by Divecoz
Trouts Dream wrote:Extra flotation could be had by placing a few extra auto-inflation life jackets in strategic locations.
:) Money is no object
Hahahahahahaha I Guess NOT!!! Hahahahaa :D :D

Posted: Mon Mar 31, 2008 11:45 am
by Divecoz
1 cubic foot is considerably larger than a 1 gallon milk jug btw and even that will only support 40 to 60 lbs depending on the type of flotation used.
I truly look at this as, possibly a false sense of security. I feel this way because I dont now and never did I know really, where my boat stood concerning flotation, once I got it home and started adding stuff! The Video does show a motor and no doubt nothing else on board! That boat is IMHO barley afloat. BUT they did have bodies / fellows aboard/on deck as I recall, THEY BTW were very careful not to rock the boat getting off ! Whats that cause you to suspect????? TURTLE !
OK of the several thousand members here on this board . Please stand up if you have ever sunk your boat. If you have ever heard of an X or an M sinking..... Hummm OK let me ask then, how often do boats of this type, who seldom to never go beyond 3 miles from shore sink?
Allow me to ask you this ? IF your having water ingress problems and you can get your motor to start and your really concerned with sinking would you think to jettison your water ballast asap! Would you agree it would be better to turtle and KNOW your staying up that maybe stay up?
If the ballast is full of air and the cabin fills with water what will the declination of the boat become? Might it sit up right?
What we need is someone who's EX got the boat in the divorce to test out some of these hypotheses on . :wink:

Posted: Mon Mar 31, 2008 2:35 pm
by Catigale
Yikes - thats 240 pounds of mass to make up.

The good news is 30 gallons is about 4 cubic feet which isnt a ridiculous amount of space to find to make you positive flotation again.

Im assuming that you get the full volume of foam as air, which is an assumption worth checking.

Posted: Mon Mar 31, 2008 2:43 pm
by Russ
How realistic is it that a Mac could get swamped?

I think I've seen a pic of one here somewhere. How did they manage to do that?

Seriously, is this a concern that a prudent sailor should be worried about. If I were in heavy seas, I'd close the hatches anyway. I suppose if you hit something like a rock and cracked the thin hull you'd be toast.
The sales video shows a Mac turned on its side with the mast held down to the dock without flooding and it popped back up. Or is it just TV and not real life?

Posted: Mon Mar 31, 2008 3:06 pm
by Catigale
We had one a few years back that we were pretty sure was swamped by an open porthole

Posted: Mon Mar 31, 2008 5:24 pm
by Divecoz
OK how about this??? Get a big truck tire inner tube. Then get either a large CO2 cannister or one of those portable air tanks from Your Favorite Auto parts supply and if you have a problem just Hook up the tube (Keep the tube up in the V berth) to the tank (either one ) pull the lever and have a coctail . If that baby/boat goes down now, you are meant to die!

Posted: Mon Mar 31, 2008 8:18 pm
by baldbaby2000
Here's one that was swamped but I'm not sure if it was determined what happened: Fran's Boat.

I note that she said the boat sat with the mast under water at about 4 O'clock. I'm not sure if the ballast was in.

Posted: Tue Apr 01, 2008 7:03 am
by Catigale
On Rogers website there are 5 guys on the swamped boat, on the smaller side, so Ill give him > 750 pounds of flotation on the :macm: as a SWAG

The boat is floating at the hull-deck joint, roughly, so there is still a fair amount of boat left to sink!

On edit: Rethinking that last statement - I dont think there is any flotation above the hull-deck line ( :?: ) which means there is little margin beyond this point - everything else is more dense than water and ergo with a bit more weight she goes down for good.

Posted: Tue Apr 01, 2008 8:16 am
by parrothead
I've seen that photo. It's on the same web site that touts the non-existent under-seat cooler and the "large racing spinnaker with bow sprit" as available options. It strikes me that there's really a lot of boat still above water. Could it be sitting on the bottom? :wink:

Posted: Tue Apr 01, 2008 9:46 am
by Russ
This photo.

What we can't tell is if there is a 300lb motor on the back and if there is any other heavy gear inside like batteries etc.

These photos seem awfully deceptive because we know a Ford Taurus isn't an ideal tow vehicle either.

LOL - Is is sitting on the bottom?

I'll say that these factory workers are in fact dry and not swimming along side with PFDs.
If I am correct, there is still flotation around the anchor locker and next to the captain's seat. My M has some up high next to the dagger board in what would make for a nice little storage compartment. My stereo is mounted through that spot and I'd like to have a place to store a few CDs and an iPod.

Image

Posted: Tue Apr 01, 2008 6:58 pm
by PatrickS
Divecoz wrote:OK how about this??? Get a big truck tire inner tube. Then get either a large CO2 cannister or one of those portable air tanks from Your Favorite Auto parts supply and if you have a problem just Hook up the tube (Keep the tube up in the V berth) to the tank (either one ) pull the lever and have a coctail . If that baby/boat goes down now, you are meant to die!
This is in essence the same as an idea that I've been thinking about off and on for some time -- namely, sailboat airbags. Essentially a very large, thin, but puncture resistent bag and a way to fill it quickly. I actually was thinking along the lines of a handcrank or foot operated air pump (all mechanical, after all, this is an emergency solution). On the threat of swamping, unroll the bag, probably in the aft berth section, or simply in the galley/vberth area if there's already alot of water, and start pumping. You could add alot of air volume pretty quickly that way. CO2 would be perhaps a nice extra, in addition to the manual pump as a backup.

I wouldn't be surprised if there is (or has been) a commercial product along these lines. Would be especially valuable to fixed keel boats with no positive floatation at all. A kind of internal lifeboat for the boat, so to speak.

Posted: Tue Apr 01, 2008 7:06 pm
by Trouts Dream
I am guessing, but during the moment of swamping I'm not sure there would be enough time to layout and inflate a large bladder.

I also noticed in the picture that the crew member in the cockpit should be up to his knees in water but doesn't look like that. Is it possible that the back of the boat was sealed off for this picture?