46' Post SF Sinks

I will be carrying a football or something that I can plug up the exhaust in an emergency.

It would be tough to react quickly enough in the event of a total failure of the system, I would imagine that the boat would be beyond recovery very quickly.

I recall that a multi-million dollar French owned mega yacht when down very quickly in rough seas and it was believed that the exhaust system caused extensive flooding. Somewhere on YF is a thread.

I agree with the fishy statement.

If it's like my 46, the exhaust is 8 inch and sits about 1/2 to 2/3's submerged all the time.
The original exhaust tube does not pass to far into the bilge from the transom.
Then there is exhaust hose to the muffler. Then hose from the muffler to a metal offset tube. ( in my case it was an 8 inch aluminum offset ) then hose again but now elevated by way of the offset tube, up to the exhaust mixing elbow.

The muffler is not elevated, but is on the same center line as the exhaust tube at the transom if that makes sense. I want to say "level" but nothing ever seems level in a boat.

In the situation above, I can see where the skipper might not even realize there was a problem until it was too late. Assuming the exhaust hose " popped" off, not exploded off.


[/QUOTE] ..Think about it, if you have a loud explosion at the dock, it might take you a few minutes to figure out what just happened. I would think a Basketball (rubber) and an airpump would be a good choice to pump up in the exhaust to block the water flow.....[/QUOTE]

Now this situation, someone heard an " explosion" of some sort. What else would you do but look in the bilge as fast as humanly possible ? How the heck could any skipper or captain NOT look into a "BOOM" ?

You're right, 8 inches is alot of water but if the crew thought quick enough, that boat woulda been saved. Once you slow the water, the bilge pumps would eventually get it and I think, well before it even got over the forward floor boards.

As for the bicycle pump, well, I've got 8 inch plumbing test plugs in my exhausts now. I fill them with a portable can of compressed air. They have a schrader valve like a bike.
It is hard enough to fill the plugs on a calm day, in the slip, with your wits about you. It'd be much worse if the boat was pitching and rolling, the waves were pushing and pulling the plug and your trying to get a fitting to hold and then pump it.
Even if you were inboard, you'd still have a time of it.
It's not a bad idea, but pretty hard to pull off.
A heavy blanket is the first line of defense for me .... after maintenance inspections, I mean.

Sad to see any boat go down. I have heard of muskrats eating thru exhaust tubes in the Hudson River? If it was an "explosion" - was it back pressure related? Be interesting to read how the facts develop. Any YF members on site?

Yeah, if the outlet was submerged one foot it would flow just under 1300 gallons per minute ... 12,200 pounds of freshwater per minute.

But, that is assuming there is an 8 inch hole ... did a large chunk of the muffler leave the building or did it just split?

Wow, that's a big piece of the muffler. Any analysis of the cause yet?

I had a good friend loose the mains approaching a bridge.

Both engines stalled and would not restart.

Alarms were going off.

He was trying to restart.

Trying to deploy the anchor.

Then bam he drifted hard into the bridge and damaged the boat.

When all was said and done it was a loose wire in the halon shut down.

All he would have to have done was hit the bypass and restart, but that was not in his emergency restart check list when there was no fire. The restart bypass is now in my muscle memory on an emergency restart.

Threads like this are helpful because not only do they help dx and prevent this type of failure but the incident ends up in your mental muscle memory and "stuff the exhaust" becomes an emergency reaction to a loud bang and sudden flooding.