Plug the hole

[Cottontop]

Hmm... not sure if that is exactly true.

If the leak is in the transom, the pressure might be greatly reduced. Maybe by planing or semi-planing, you could get the leak out of the water, depending where it is.

 

[dhays]

I have seen that before and think it would be a good thing to have on board. I also have rescue tape on board for issues with hoses etc.... However, I have to admit that the rescue tape is stuffed into a lazarette somewhere. Not much help if I have to go hunting for it, or it is in a location that is under water. The same would be true of Stay Afloat. Only works if you can put your hands on it quickly. I really need to organize my boat better.

 

[Giggitoni]

Six feet under water would be a differential pressure on the hull of about 3psi, no?

Yes. The pressure at a through hull at the water line is zero. Figure about 0.459 psi per foot. So hull breaches are low pressure. However, at times, depending on the size of the hole, can be very high volume!

 

[danderer]

Interesting. All of those examples seem to be low pressure issues. I am not sure a through hull, hose, or crack failure on my boat would be that low pressure?

Yup, the examples appear that way. I see their FAQ says:

How much pressure can it handle?

We have tested Stay Afloat to 19.15 PSIA at 3 meters deep for 24hrs with no compromise. It also depends on how much material you use and how big the damage area is, common sense, the bigger the hole the more you use.

 

[Lobstah]

I read an account some time ago where a guy's pumps were not keeping up. He closed the raw water intakes for his engines, disconnected the hoses and ran the engines to the yard near WOT with someone watching the water level so he didn't run the engines dry.

Don't know if that was an urban myth or not!

A friend of mine did this while running from New Hampshire down to Fl back in the 80s. They took the "outside" route past Georgia, were roughly 25mi offshore, big seas, hit a container. At least, that's what the coast guard said it was.
His initial indication that something was wrong was his boat doing a slow 360 while on autopilot. He reset course, reset autopilot, and a very soon the boat did another 360 turn.
He quickly went below decks and discovered water coming in through a hull puncture in near the bow. They hailed the coasties, who dispatched a helio.
In the meantime, Mike did exactly that, as the pumps were not keep up, and it was the only means he could think of to get more water out of the boat.
The helio showed up and they lowered 2 more pumps in an attempt to save the boat...even that wasn't enough.
Crew was hoisted up, and Mike was the last to go, and on the way out the last thing he did was grab his small hand-held Garmin GPS, quite the tool at that time, and stuff it in his pocket.
His crew was laying down in the main cabin due to rough seas. They said that they had heard a sort of "bump" when the boat came down off the top of a wave, but didn't really feel anything.
Think the boat was either a 38' MT or a 40' Albin.

So no, don't think it's an urban myth.

 

[psneeld]

Maybe not urban myth...but definitely arguable that it may be or not be practicable for many vessels.

 

[BlindHog]

Keep in mind that the rating of a bilge pump is at ITS outlet not the end of the hose. You need smooth bore hoses which most trawlers have, plus a short run. Your outflow is actually less.

 

[Padeen]

I keep a heavy tarp on board with lines attached which will reach around the hull. The plan would be to drop the tarp off the bow and work it into place to cover hull damage and slow water intrusion.

Aka: fothering sail, or fothering tarp; as you like

 

[danderer]

I have to admit that the rescue tape is stuffed into a lazarette somewhere. Not much help if I have to go hunting for it, or it is in a location that is under water. The same would be true of Stay Afloat. Only works if you can put your hands on it quickly. I really need to organize my boat better.

Hmm. Good point. I've got tape and some plugs and hose clamps, but couldn't tell you off-hand where they are.

Maybe I need to make a "keep-from-ditching bag" holding all this stuff in one place.

 

[what_barnacles]

You guys are way over thinking this.

just wrap that hull breach with a blue tarp.

 

[MurrayM]

Saw a product that made sense, but can't find it now.

It was a flexible rubber/plastic disc on a stick...you push it through the hole, then it opens into its round shape and water pressure forces it against the hole.

Ring a bell?

 

[Al]

Greetings-
Through out Southeast Alaska, on commercial craft, tugs, fishing, this product is often found somewhere in the inventory on board. While it is not advertised as the quick fix the 'Stay afloat' advertises, from experience this product will begin the process of leak stopping even as it remains in its initial flexible status.
This product in many cases is known to become the permanent fix.

Read the detail to gain a level of desire to add this to your emergency repair list.
Regards,

Al-Ketchkan

Pettit Splash Zone Compound Kit

 

[BruceK]

Saw a product that made sense, but can't find it now.

It was a flexible rubber/plastic disc on a stick...you push it through the hole, then it opens into its round shape and water pressure forces it against the hole.

Ring a bell?

Like an IUD?

 

[menzies]

You guys are way over thinking this.

just wrap that hull breach with a blue tarp.

Hah, I have a easer and quicker solution.

I am just going to tell the wife to stick her big arse in it!

 

[High Wire]

Before you depend on pulling off an engine intake hose for dewatering, close the seacock and try it at the dock. Now add in that it may be under water in an emergency. A lot harder than you think.
And if you have pre-installed plumbing, don't forget that you will need to close the seacock first which means you will need to shutdown that engine or risk impeller meltdown.

 

[dhays]

Before you depend on pulling off an engine intake hose for dewatering, close the seacock and try it at the dock. Now add in that it may be under water in an emergency. A lot harder than you think.
And if you have pre-installed plumbing, don't forget that you will need to close the seacock first which means you will need to shutdown that engine or risk impeller meltdown.

Yeah, no way I could pull it off under those circumstances, but I do have a sharp knife and a hacksaw. Cue the hose above the seacock.

 

[BlindHog]

Many sport fishing boats, Cabo's in particular, have a y in the intake so you can switch from the raw water intake to a crash pump with a strainer. It wouldn't take much to retrofit depending on your layout.

 

[Peter B]

....
And if you have pre-installed plumbing, don't forget that you will need to close the seacock first which means you will need to shutdown that engine or risk impeller meltdown.

No, I don't think so. If it was pre-plumbed for this function, with a y-valve in the intake, with one hose to the through hull, and one to a strainer in the bilge, it would mean a simple flick over to the bilge side would be quite easy, leaving the normal intake seacock open, so that when the bilge was drained enough there was a danger of sucking air, s simple flick back the other way would again have the engine drawing from the through hull normally.

 

[Al]

Could one of the "Engine raw water pump' advocates offer what a gpm discharge would be? Asking only as I witness raw water discharge from boats there are dry exhaust boats that piss a steady stream and then with raw water exhaust systems, the discharge appears less in terms of volume.
I am sure the size of the engine size/demand are in play, it is the outcome of all the preplanning. Is it worth it or added to the mix as an available source given the urge to plumb the system? Its there so lets do it project?

Stated as one who would perhaps,add another bilge pump in the system as a back up. (I have four pumps in line now in a 27 foot boat-(Belt and suspenders mentality)


Regards,
Al-Ketchikan 27'Marben Pocket CRUISER

 

[dhays]

Many sport fishing boats, Cabo's in particular, have a y in the intake so you can switch from the raw water intake to a crash pump with a strainer. It wouldn't take much to retrofit depending on your layout.

Yup. I have looked at some systems that allow for a freshwater flush fitting along with an emergency bilge pump. I would like to do it as soon as I feel up to tackling those very stiff raw water hoses.

 

[bcam]

Hah, I have a easer and quicker solution.

I am just going to tell the wife to stick her big arse in it!

Then death will come faster than drowning?

 

[High Wire]

No, I don't think so. If it was pre-plumbed for this function, with a y-valve in the intake, with one hose to the through hull, and one to a strainer in the bilge, it would mean a simple flick over to the bilge side would be quite easy, leaving the normal intake seacock open, so that when the bilge was drained enough there was a danger of sucking air, s simple flick back the other way would again have the engine drawing from the through hull normally.

Agree if you have a Y valve. They only factory install I've seen used a seacock, tee , strainer, and a gate valve

 

[ranger58sb]

And if you have pre-installed plumbing, don't forget that you will need to close the seacock first which means you will need to shutdown that engine or risk impeller meltdown.

I've been thinking on a way to have the alternative supply line -- with its own shut-off valve -- already installed into our flush fittings. If solved, then the system would work more like crash valves: (partially?) closing the real sea cock to enable the alternative feed.

I'm not sure it's possible to pull the blocking port and insert the flushing adapter (ideally already made up with supply hose and bilge strainer, etc.) while the engine is running, though. I suspect at the very least, big mess... although if this were to actually be necessary there's likely already a big mess anyway.

Many sport fishing boats, Cabo's in particular, have a y in the intake so you can switch from the raw water intake to a crash pump with a strainer. It wouldn't take much to retrofit depending on your layout.

That's likely what our Groco SSC fittings are. Not as elegant as real crash valves, but potentially usable.

No, I don't think so. If it was pre-plumbed for this function, with a y-valve in the intake, with one hose to the through hull, and one to a strainer in the bilge, it would mean a simple flick over to the bilge side would be quite easy, leaving the normal intake seacock open, so that when the bilge was drained enough there was a danger of sucking air, s simple flick back the other way would again have the engine drawing from the through hull normally.

Yes, I think it could be that simple. An issue in our case is the throughput; our flush fitting adapters reduce the "emergency" (or flushing) inlet to garden hose size... so not the same flow rate as the main inlet. I have spoken with Groco about an alternative to the standard flush adapter and to be used more as a crash valve wannabee rather than just for flushing, that would allow more flow and also be able to be fitted with shut-off, supply hose, strainer, etc -- and then connected to the main flush fittings in advance.

Could one of the "Engine raw water pump' advocates offer what a gpm discharge would be?

I'm sorry I have no clue. As it is now, the flow through the garden hose adapter fitting will be less than what the raw water pump pulls through the 2" ports. I suspect pull could run the risk of collapsing the emergency supply hose unless some sturdy stuff is used. And then a strainer at the bilge end is likely critical, assuming all sorts of stuff could wreak havoc on the supply.

Yup. I have looked at some systems that allow for a freshwater flush fitting along with an emergency bilge pump. I would like to do it as soon as I feel up to tackling those very stiff raw water hoses.

In theory, I think it makes sense and it wasn't expensive to just add the flush adapters. Remains to be seen whether theory would pan out...

-Chris

 

[stubones99]

I read an account some time ago where a guy's pumps were not keeping up. He closed the raw water intakes for his engines, disconnected the hoses and ran the engines to the yard near WOT with someone watching the water level so he didn't run the engines dry.

Don't know if that was an urban myth or not!

A safer bet is a fast flow bilge pump on the prop shaft, if you have space.

It runs constantly, and won't burn up if run dry. It is an open frame centrifugal pump that you can mount without pulling the shaft. Even their smallest pump will work (in either rotation direction) with several hundred gallons per minute. If you have a bigger water leak than that, you're probably not saving it, except by running it aground.

Fast Flow Pumps - Bilge Pump Design

I think insurance companies should discount insurance on boats equipped with these pumps. I'm not affiliated in any way to fast flow... just a believer.