Flooding Emergency -- Checklist

[senormechanico]

Last on the list:
Next time, buy a multihull.

[Cruisingscotts]

I have a really gross story I won't repeat about a Chief engineer I used to work for who loved to "taste the water" to see if it was salty, lets just say freshwater is not the only thing contained in large tanks on vessels......

[IdoraKeeper]

I am familiar with an accident where the boat was rolled, dismasted and holed by its own mast before the rig could be cut away. The flooding was stabilized by the crew of man and wife, but the leak prevented de-watering. Flooded batteries began to outgas chlorine which rendered the below deck spaces uninhabitable. The crew was forced outside in very severe conditions. The Canadian Coast Guard delivered de watering pumps by helo and followed that with a cutter and a tow when conditions improved.

The lesson to me is you may stay afloat but your troubles may not be over. This couple never abandoned their vessel, when I saw it next...the damage was awful. My admiration for the crew and their toughness is palpable.

[RaymondR]

I was an offshore oil driller for a fair chunk of my life and consequently was exposed to the strategies the big floaty blokes employ. Their chief defences are double hulls, void spaces and compartmentalization. They seldom have the capability to move massive volumes of water once it gets in. The pumping out is generally carried out be salvage personnel.


After inadvertently leaving the top off the sea strained on my boat when the travel lift put it back into the water I was horrified at the speed the boat started to fill up. The sea strainer has a 2" valve on it so all I had to do was close it. However this got me pondering on the subject of flooding and defences in a 39' sail boat.


Oil drillers spend most of their life pumping fluids around and one of the things you quickly learn is that if you want to move a lot of fluid you need a big pump.


A really paranoid person would rig a belt driven 6" suction, 4" discharge centrifugal pump under the engine. The pump could fairly lightly constructed as it does not need to pump against a high head. A flapper type check valve would stop back flooding. No clutch, just hit the starter and away she goes.


I originally had separate locker covers and seat cushions, pain in the butt, take away the cushion then the locker cover to get anything out then two bits to put back and the locker covers were not as big as they could be. Jig sawed all the excess and had the upholsterer fix the cushions onto the covers, There are enough of them with a good plywood backing to jam up against a good range of holes in the hull.


Tried the fothering trick on a ferro boat that had a fairly large hull breach, it sort of slowed the leaks down but the jagged mesh and rebar ends tore the fotherer when the water pressure forced it into the holes. Realized later that grain of some sort or rice mixed into a slurry with flour and water would probably have done a better job and quicker to do.


Battery flooding is a problem but if they are wired so that you can put garbage bags over them and tape it down or tuck it underneath the trapped air bubble might stop them sea water flooding. I am rehousing mine and was thinking of having the hold downs made so that they went over the tops of the filler holes and sealed with a rubber gasket so that I could vent them and put low water probes into each cell. Since I am putting them down on top of the keel for better CG reasons and they would flood more easily there this has now become part of that jobs implementation plan.


Involved check lists and complex response action not good in flooding incident, rapid instinctive of pre-implemented, in place solutions only way to go.

[Snowpetrel]

Dock, seems like a good list plus comments from all, I'd add that I think finding the damn leak has to be a first priority. Hopefully an effective low mounted bilge alarm or two should give you early warning , with a regular testing routine as part of your predeparture checks is a good idea. Many commercial vessel sinkings or capsizes could have been avoided if bilge alarms had been working.

So first off in my book is to find out if the water is flowing from fwd or aft into the bilge well and narrow down the search before the water rises too much. You should then be able to move towards the source and narrow it down further.

I'd probably not shut down the engine unless it was clearly the raw water intake or exhaust at fault. Though the quiet might help hear the leak. But if water reaches the starter motor you might not get it going again, and the extra voltage is going to help HF and pumps work better.

I'd consider heaving too or running off to reduce motion. In light airs motoring down or up swell will steady her up some.

Heading for the nearest hbr or sheltered beach might also be a smart move. As could getting away from a dangerous shore if need be.

Measure the water depth so you know if you are winning or losing, and confirm the pumps are actually pumping overboard. If the pump outlet goes underwater and the pump fails it's quite possible for the water to start backflooding through the pump.

I'd almost always attack any leak from inside first. Even a poor internal patch can substantially reduce the amount of water coming in, as can raising the hole by heeling the boat. Fothering can work, but in a swell its going to be hard to stop it flapping, and you can't really keep the boat moving unless you do a real good job of securing the material.

You have time, much more that it would probably seem at first. Even a large hole takes a long time to sink a yacht. If the leaks so big the boat is in danger of rapidly sinking you should know exactly where it is, and roughly how big it is, ie polinya star...

Any spare hands onto buckets of they are idle It's amazing how fast they can work, and they don't block. And it utilises all that adrenaline... Just be aware that bailing into the cockpit doesn't work if it's the cockpit drain that sinking the boat, or someone has closed the cockpit drains.

Don't forget things like anchor lockers, gas lockers or cockpit floor hatches can result in additional leaks as the boat settles.

Have a defined abandon ship water height mark, where freeboard becomes dangerously low, or the boat is at risk of catastrophic flooding through companionways or other vulnerabilities. Powerboats need to consider stability as free surface ramps up. Most keelboats have adequate (but reduced) stability when partly flooded.

Trim can be a big issue as a boat settles, hence the added value of bow and stern watertight compartments. Trim away from the pumps is nasty..

On some boats closing the cockpit drains in calm weather can buy you added buoyancy and effective freeboard.

In my experience pumps often fail in a bad flooding scenario where debris is a big issue. So I prefer to focus on finding and reducing the leak ASAP.

I have a decent DC kit aboard. I've got something about it on my ramblings somewhere.

[Dockhead]

Wow, this is a cornucopia of great ideas. Thanks to everyone who contributed. I am revising my checklist and will post it with comments tomorrow.

[wrwakefield]

Your checklist is thorough, Dockhead.

I didn't notice a mention of waterproof 'maps' showing all through-hull locations (differentiating between above and below waterline either with color coding or separate maps...)

Likewise for emergency and ditch equipment.

I find both invaluable.

Great thread. Much to learn.

Cheers!

Bill


Bear with me: My touch screen device's auto-correct rarely is; but at least the text is tiny...

[Dockhead]

Originally Posted by wrwakefield

Your checklist is thorough, Dockhead.

I didn't notice a mention of waterproof 'maps' showing all through-hull locations (differentiating between above and below waterline either with color coding or separate maps...)

Likewise for emergency and ditch equipment.

I find both invaluable.

Great thread. Much to learn.

Cheers!

Bill
.

I have a laminator on board, and do have laminated checklists for abandon ship, mayday procedure, fire procedure, plus a scheme showing through-hull locations.

I don't need the through-hull map as I could find them all even blindfolded, which is why I would be the primary searcher in case of a leak which didn't have an obvious source, but I keep it just in case someone else needs to know.

[boatman61]

Dockhead.. you missed the essential 'If All Else Fails' piece of Kit..
Even if its a multihull.. as suggested by some..

[Uricanejack]

!#$%^^&*((
I'm giving up sailing and buying a motor home.

[wrwakefield]

You set a great example, Dockhead.

Well done. I always welcome such meticulous preparations when I crew on another vessel.

Cheers!

Bill

[barnakiel]

IMHO you can only save the boat if you know where the water is coming from and then if you act fast and act effectively. This is next to impossible in most big cruising boats. Buy one with many truly watertight divisions (e.g. an Amel). In any boat: modify extensively your bilge pump and alarms inventory. Boats come from boatyards with SILLY pump out capacity.

Also, to add to my chances, I would add water intrusion alarms throughout the boat.

And my list looks like this:
1) start the pumps,
2) make sure the engine (or genset) is not flooded,
3) start the engine (or genset),
4) find the leak,
5) limit the flow,
6) cool down, reassess, readjust.

You want deep bilge pumps that are capable of pumping out your boat displacement in 10 to 15 minutes.

b.

[bill352]

Just a little thing, but when you lead that hose over the side from the crash pump, be sure it is well secured to the pump. Otherwise, it is just waiting to slip off and foul your prop.

[Dockhead]

Originally Posted by bill352

Just a little thing, but when you lead that hose over the side from the crash pump, be sure it is well secured to the pump. Otherwise, it is just waiting to slip off and foul your prop.

Very good point. That is why I mentioned assigning a crewman to tend it.

[Dockhead]

Originally Posted by barnakiel

IMHO you can only save the boat if you know where the water is coming from and then if you act fast and act effectively. This is next to impossible in most big cruising boats. Buy one with many truly watertight divisions (e.g. an Amel). In any boat: modify extensively your bilge pump and alarms inventory. Boats come from boatyards with SILLY pump out capacity.

Also, to add to my chances, I would add water intrusion alarms throughout the boat.

And my list looks like this:
1) start the pumps,
2) make sure the engine (or genset) is not flooded,
3) start the engine (or genset),
4) find the leak,
5) limit the flow,
6) cool down, reassess, readjust.

You want deep bilge pumps that are capable of pumping out your boat displacement in 10 to 15 minutes.

b.

I was slightly traumatized by the story of the boat which went down in the ARC where the crew was never able to figure out where the water was coming from.

But I've been "war gaming" this in my mind, and I just can't understand this, at least in regard to my own boat.

There are two main branches of this scenario -- hull breach, or no hull breach.

Let's assume that a hull breach is practically impossible without a noticeable collision (excluding a certain Oyster recently).

So if we're dealing with water coming in without a hull breach, there are a limited number of possibilities:

1. through hulls
2. exhaust/raw water system
3. siphoning if an above the waterline through hull is below the waterline (on a heel, for example).
4. keel joint
5. shaft seal
6. rudder seal
7. anode bolts

That's it.

As someone above said, you can see from the situation in the main bilge from what direction the water is coming from.

So if it's coming from aft, I can check, on my boat, every possible point of entry in about 2 minutes. Less than 1 minute if we exclude the rudder seal. Even less if coming from forward. Close all the through hulls and the only thing left is rudder and shaft seals, keel joint, anode bolts, and I think only shaft seal, of these, is capable of such a volume flooding that the normal bilge pump can't keep up.


This is maybe not rocket science. I start to wonder whether the people who lost their boat in the ARC just didn't know all their through hulls. There was some speculation that it was caused by a rudder seal, but how much water can come in around a bad rudder seal? It's barely under water (not at all on my boat), and the gap must be a very small area.


The key thing, besides knowing where to look, is to start looking before the sole plates are floating.

Ergo, bilge alarm is possibly the key piece of equipment, even more than pumps.