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TOPIC: Strategy for a Flooding Vessel

Strategy for a Flooding Vessel 2 years 2 weeks ago #2021

  • Dick
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Submitted: Dick Stevenson, s/v Alchemy 6 Feb. 2014
This article outlines a strategy for managing a flooding situation on board your vessel. By flooding I mean any ingress of water which is unable to be stemmed by pumps: i.e. you are sinking. A planned and practiced strategy is crucial as flooding calls for specific directed actions, quickly executed.
I am primarily addressing the typical cruising boat, a husband/wife team on any size boat, although much of the planning can easily be considered for fully crewed vessels. Even if you often have guests, they are unlikely to be helpful in a situation where quick, practised action is necessary.
The Synopsis of this Strategy
The bottom line in a flooding situation is the need to find the flooding and find it fast. As water rises it covers the leak making what was, at first, an easy visual inspection, turn quickly into one done by Braille: by feeling around. Clearly, visual inspection is far quicker and surer. Most of what I suggest is to allow the leak to be found fast.
As a general rule, most of us get less competent in emergencies. Obvious alternatives are not thought of in the anxiety of the moment. Planning ahead, making diagrams and, most important, practicing will mitigate this tendency.
1. Set up your boat to allow you to quickly find and respond to leaks.
a. Anticipate vulnerabilities: First, know your boat and try to anticipate all possible areas of vulnerability to flooding. Make a diagram with salient points highlighted.
i. Make sure all seacocks are accessible and able to be worked by your least strong crew. If there is a seacock which is largely inaccessible, say only by taking apart woodwork or by emptying a locker, consider access cutouts or re-thinking your storage. Relocating that seacock is not an unreasonable choice.
1. Labelling seacock locations on cabinet/hatch/floorboards can help, especially those vessels with many thru hulls.
ii. Include rudder, drive shaft, and transducers as areas for flooding potential as well.
iii. Track all your hoses, especially those from seacocks. You will find chafe points you can protect, and you can anticipate vulnerable areas such as distribution manifolds.
iv. You cannot do much about your vessel’s sump, but one should keep in mind that the less sump you have, the less warning you will receive and the more quickly water will cover and obscure wide areas.
v. The same goes for structural “pans” which obscure hull inspection and direct water in difficult to predict pathways.
b. Early notice: high water alarms* are absolutely essential as they can give immediate warning of any unusual water accumulation. They must be able to be heard in the cockpit of a closed up boat with the engine running. Many a crew has first found flooding by discovering their floorboards afloat. If we have heard the story told, the crew was very lucky. I suspect many who found their floorboards afloat never found it possible to tell anyone their story.
i. One option is an alarm which sounds every time the electric bilge pump operates from its float switch. We have a dry boat so pump activation is always motivation for bilge inspection.
ii. Another option (and there is no reason not to do both) is a dedicated high water alarm ready to go off when water gets just a scooch higher than the level where your bilge pump activates.
iii. If you have two (or more) bilges it helps when the alarm sounds are distinct for each bilge so as to have an early indication for a search area.
c. Floorboards: the crucial floorboards for inspection must be able to be removed quickly by the weakest member of the crew.
i. After a period of high humidity, make sure your floorboards are not too swollen to remove. Shave them if necessary.
ii. Review all floorboards that need to be lifted for a complete flooding inspection. If screwed down, refit to a floorboard lock that is quickly released (a distant second best, store a charged electric screwdriver ready at hand).
d. Speed: the quicker that the leak can be isolated, the narrower the search area.
i. Some boats have the engine area bilges separated from the living area bilges. A quick look determines which area is flooding and narrows the search area.
1. Make separate diagrams as to which seacocks, transducers etc. drain into which bilge area. This is not always obvious, especially with structural pans. One way to clarify is to pour a glass of water near a seacock and track where the water goes.
ii. If you have a “one bilge” boat, consider a dam at a strategic point. It does not have to be high or strong: just a water stopper. Water can and should spill over, but make it high enough to allow alarming it to narrow the search area. **
e. Pumps: the more water that can be removed from the boat automatically, the more time to find the leak when it is most easily found.
i. This means electric bilge pumps for most of us.
1. Pumps benefit from clean bilges, flushed regularly.
2. They also benefit from good voltage and unrestricted amperage. Review, check and/or upgrade your wiring.
ii. It also means that manual bilge pumps have no place in this strategy:***
1. They are a dangerous distraction from the main goal of finding the leak and finding it fast.
2. Most cockpit mounted pumps (with their short 12 inch handle) move only a moderate amount of water and are hard to sustain energetically.
3. A big pump like an Edson with a 3 foot handle is a wonderful piece of kit, but is still not a wise use of manpower. You do not want 50% of your search capacity (2 person crew) pumping when that pumping is quite unlikely to keep up with sustained flooding and the goal is to find the flooding fast. Two people should be searching for the leak.
2. Refine the strategy for your boat:
a. The alarm indicates flooding. This is one alarm that should get immediate action and the action should be previously thought through and practiced: this is not a time to be spontaneous. One or two floorboard lifts should indicate whether there is a worry and where to initially concentrate your search.
b. From here each vessel’s detailed flooding procedure plan will start to be unique to its own particular design. I am including Alchemy’s flooding plan (shown below) as a way to address the details, the compromises, and some ancillary considerations for this serious event. The following will show how we have taken the above strategy and made an operating procedure for our vessel. Each vessel will differ in the details, but generally the principles will pertain.
3. Practice!!
a. There is no way to emphasis this enough. You cannot just write a plan. You must practice using it to make sure your plan works and you can work the plan.
*Easily obtained high water alarms can be had very inexpensively by any vendor who sell household products. These self contained units are often powered by 9v batteries so they are independent of ship’s power grid. They should be tested at regular intervals.
**Often, a natural area for a small dam is where the engine room bilge meets the living area bilge. As said, the dam does not have to be high, but an added benefit is that small inevitable spills of oil, diesel, coolant, etc. stay contained and are easier to clean and less likely to be pumped overboard. They also give quick notice of engine drips/leaks.
***Often articles in magazines reflexively mention manual bilge pumps. I have worried that many boat owners believe going to their manual bilge pumps is a first response to flooding. A casual survey of boat owners seems to confirm this.
Flooding plan for Alchemy:
A. Procedures to be thought through and practiced in advance.
1. Flooding should be first brought to attention by a high water alarm or bilge pump alarm.
a. Which high water alarm is sounding should differentiate whether the forward or aft section of the bilge is flooding [the bilges are separated and water must reach the floorboards to fall/flow to the other bilge]. If unsure, raise floorboards where engine bilge meets forward bilge (next to galley sink) and see which side is full and/or which way the flow is going. This determines search area.
2. Test water for salinity; if fresh water, breathe easier (unless sailing in fresh water). Make sure it is not diesel.

IF IT IS FLOODING, then Ginger and Dick work previously determined areas of inspection.
a. Locating the leak takes precedence over most everything because as the water level rises finding the leak becomes more difficult.
b. If extra crew, set them up in cockpit with manual pump-handle in bottom step.
c. THINK! Ask ourselves what has just been done/happened (heard a bump, tacked, started genset, filled water tanks etc.)
d. Watch footing for holes left exposed by floorboard removal. Not a time for injury.
e. At some point, earlier rather than later, consider donning life jackets/vests or ensuring they are ready at hand.
f. At some point, again earlier rather than later, reach out to make contact. This could include:
i. Calling out a Pan Pan Pan and making a report of vessel’s location and the nature of distress.
ii. Hitting the VHF distress call button (DSC button) and hold for 5 seconds--we can always cancel later.
g. Consider same with EPIRB.
h. Consider heading the boat toward a grounding place, a beach preferably, and put on speed. (It is likely we will be on autopilot and this will entail only a quick turn of a dial.)
i. Consider starting the engine as electric bilge pumps will pump more water with increased voltage.
2. Consider setting up high capacity electric bilge pump (one automatic medium capacity pump is always available). Attach hose (stored in forepeak starboard side under) with quick attachment and put out portlight or cockpit. Tie in place. [Note: a plan is in the works for this to be made automatic as this interferes with the primary task of finding the leak.]

1. Check aft of engine (if clear, then rudder assembly, genset and thru-hulls aft are ok; go to #3), if water is flowing, then:
a. Turn genset off if it is on, then turn off water for GS at manifold.
b. If flow stopped, the genset was the problem, if still flowing, then:
2. Check rudder shaft area.
a. Remove starboard lazarette.
b. Rudder shaft, 4 cockpit drains, genset exhaust & propane locker drain should be visible. [On ALCHEMY, there are a number of thru-hulls at or just above the waterline that have no valves (such as the cockpit drains). I consider this a design compromise I am not happy with, but have decided to live with.]
3. Two areas to check midships aft (that go into aft bilge area).
a. Three seacocks are under head sink. Turn all off after inspection.
a. In wet locker and head are 3 thru-hulls just above waterline (electric bilge, scupper, shower sump).
b. Port side locker has scupper discharge and a no longer used, now plugged, refrigeration outlet
b. Check engine area for leaks, especially shaft area.
a. Check engine exhaust and manual bilge pump discharge thru-hulls outboard in engine room.

1. Check bilge at most forward floorboard for water flow
a. If Yes, then:
i. Check and turn off deck wash seacock.
ii. Check depth and speed transducers.
iii. Next is hull integrity.
b. If No:
i. Check main seacocks (two, near mast step).
ii. Check distribution manifold (close genset seacock if not in use).
iii. If all ok consider starting engine for mobility and for good voltage for pumps.
iv. Check likely hose lengths for breaks.
c. Check galley seacock and turn off.
d. Hanging lockers either side may drain either side of bilge barrier.
i. Port side also has old refrigeration thru-hull, plugged.

1. Checking keel bolts (just one in aft bilge area).
2. Checking for siphon action: bilge pumps, engines, toilet, galley sink, PSS Shaft Seal bleeding hose, etc.
3. Checking hull integrity around best guess for ingress.
a. Tack over to get opposite side out of water.
4. Checking to see if water level is decreasing with seacocks closed; if so breathe easier as leak is in a hose (and with seacocks closed should stop) and we now have time to find. If not….
5. Bailing is an option!
6. Do not stop looking for leak and bailing until water drives you out. The best chance of survival is to keep the boat afloat.
7. At some point, prepare life raft, grab bags, etc. for abandoning ship, then return to searching.

B. Hull holing equipment and LOCATIONS
1. Bungs of various sizes in red bag in bottom step of companionway ladder. (I differ from many by not liking bungs attached to each seacock, although they do have to be very accessible. First, in a flood they may be difficult to untie, see and/or work with if tied to the seacock. They also collect dirt, grime & mold and are continually damp which undermines the swelling expected once banged in place.)
2. Collision mat in forepeak forward
3. Emergency Hull Repair Kit with waterproof epoxy near water heater.
4. 1\4” plywood 14”x 3’ under starboard settee cushion with many other various options.
5. 5200 (2 fresh caulking gun size tubes) and sheet rock screws near water heater.
6. A quite creative suggestion (I suspect from the “old salts” manual) is a lead sheet, pre-perforated, with sheet rock screws.

C. Seacock and thru-hull locations (The bag of bungs is in the bottom companionway step). (In our safety manual, in addition to the above text, there are 2 pages of diagrams, port and starboard side, giving visual indications of where the thru-hulls exist.)
1. Hull openings below waterline: 7 seacocks (listed below) plus propeller shaft and two sending units for instruments (under floorboards forward of table).
a. Two seacocks under floorboards in front of mast.
b. One in the port side forepeak bilge locker under cushion in middle.
c. One under floorboards near galley sink.
d. Three under head sink.
2. Numerous hull openings just above the waterline, again see diagrams.
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Strategy for a Flooding Vessel 2 years 2 weeks ago #2022

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Hi all,
I apologize for the formatting, but did not have any idea of how to remedy. I believe all the important information is clear enough, but do come back with questions/comments etc.
This article is part of the Cruising Club of America's Safety at Sea section of their web site and also was published by Steve D'Antonio in his ongoing series of articles on his web site.
My best, Dick Stevenson, s/v Alchemy, Lerwick, Shetland, Scotland

Strategy for a Flooding Vessel 2 years 2 weeks ago #2027

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On our delivery trip to Long Island Sound after purchasing Aleria in Oxford, MD on the Chesapeake, we went the long way around out of the Chesapeake and offshore to stretch her legs. We had several test sails in the Chesapeake before that without any issues. About half way up the coast, we started taking on water. We didn't notice until it began sloshing up through the floorboards when we heeled. We quickly took to the emergency pumps and managed to get the flooding under control.

It turned out to be a dried out packing gland which gave way slowly. We were able to see the leak once the water was below the shaft. We merrily pumped our way up the coast through the night and anchored off the CG station off Sandy Hook to tighten the seal and make repairs before heading up the East River.

After that we made a detailed diagram of all potential water ingress spots and replaced the packing gland and through hulls when we hauled out.

Very good detailed paper, Dick. Excellent advice for short-handed crews, too. Thanks for sharing.

Strategy for a Flooding Vessel 2 years 2 weeks ago #2062

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Daria and everyone,
Your email and a personal one from another OCC member who found their floorboards awash yesterday underline for me the importance of the alarms I mention in the article. Both of you had shaft leaks from shaft seal and glands. That is a relatively easy leak to find in many vessels. When floorboards get wet, many vessels thru hulls would be underwater making a leak in those areas much more difficult to locate. Early warning alarms, low in the bilge, give often crucial extra minutes to find the leak, not to mention the items/equipment etc. that get salt water wet when the floorboards start to float.
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Strategy for a Flooding Vessel 2 years 1 week ago #2067

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Useful account Dick - thanks. Shall be installing a float switch and alarm in the near future.

Strategy for a Flooding Vessel floorboarda 2 years 1 week ago #2078

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Dick's suggestions are great. One point to add
If the water gets above the cabin sole, and the hatches are not fixed down, they float away and it becomes VERY difficult to move around the cabins. I met the skipper of a 70 foot. Oat he lost because of that.
Hatches must be easily opened. As Dick says, having them screwed down is a bad idea.
Our hatches are all hinged, and when closed they fasten automatically, just as all doors do when slammed shut.
I feel this is an essential safety feature of boat design.
We made our hatches large, which is all the safer. Over 90% of Milvina's cabin sole consists of hinged hatches.
It would be a lot of work to change many boats to this condition, but it is not too hard to add hinges and catches to most hatches in cabin sole
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Strategy for a Flooding Vessel 2 years 1 week ago #2079

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Hi Neil,
Excellent suggestions. I have never come across hinged floorboards, but they make a lot of sense and could make for a good winter project. Many boats, I believe, would lend themselves to hinges and a latch of some sort rather than pins and a locking device.
When floorboards start to float, moving about in most boats would be very likely to lead to a broken leg or worse. If floorboards are floating, it is probably time to focus efforts on abandoning ship, or at least the preparations for doing so, as finding a leak in deep water would be quite unlikely. When prepared to abandon ship, continue looking for the leak and "step up" to the liferaft.
With alarms one should never find one's floorboards floating. To me, bilge alarms should be required on every vessel when built: well installed by the manufacturer. They are a very easy installation, however, something within every boat owner's capacity.
Thanks for your thoughts, Dick Stevenson, s/v Alchemy

Strategy for a Flooding Vessel 1 year 9 months ago #2287

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Dick, Last spring, we were heading offshore from Wightsville Beach, NC to Beaufort, NC, when a half hour after we left, I reved the engine hard to make Beaufort before dark. fifteen minutes later I noticed water over the floor boards. I quickly jumped below and tasted the water. It was salty so we were taking on water. Next I checked the shaft seal and saw we were taking on water through it. I immediately cut the engine back and the inflow stopped. When we got back to Wrightsville Beach I had a mechanic come and check it for me. He tightened that shaft seal and said that often the bellows on the Last Drop Shaft loose flexibility and when you push the engine hard the prop pushes the shaft forward and when you have a V-Dive, as we do, the shaft may actually move slightly forward as it pushes the V-Drive up just enough to allow water to come in. Lesson learned, always check your shaft seal and tighten it periodically and or replace it(as we just did)

Strategy for a Flooding Vessel 1 year 9 months ago #2291

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Dear Scott,
Glad it was such a happy ending although I suspect there was some yucky clean up and that some items below the floorboards were not happy.
This occurrence is a good argument for, at least once a season, putting your propulsion engine through its paces. For me, I run it WOT (wide open throttle) under load for 5 minutes (Your diesel should be fine with this, but, if uncomfortable, go at 80% throttle). Also do some aggressive stops and starts such as might occur in an emergency drill in a marina where things go pear shaped. I also have a hose clamp just outside the "collar" of my Shaft Seal so it could only slip minutely if the worst happens. A sacrificial zinc so placed would do the same job.
My best, Dick

Strategy for a Flooding Vessel 1 year 7 months ago #2440

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I have also experienced flooding above the floor boards, on my first yacht. Motor sailing between shoals, single handed. Luckily I was able to find the leak almost right away, it turned out the engine water inlet hose was torn. So I learned the lesson the hard way and now have a plan as well, although not as extensive as yours.

I have one addition to your plan: I find my electric bilge pumps do not have the kind of capacity needed for a bad flooding situation. I therefore have a normal household submersible pump with much more capacity, running on 230v. So, after switching on the bilge pumps, my plan includes starting the engine, switching on the DC-AC converter and shoving the submersible pump where it does most good. This almost triples my pump capacity! It might be a good idea to switch on the engine anyway: bilge pumps use quite some amps, so keeping the batteries full is important. Also, starting the engine once the some parts are flooded may be difficult, whereas keeping a a diesel engine running in wet condition is no problem at all.
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Strategy for a Flooding Vessel 1 year 7 months ago #2444

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Dear snelem
Thanks for your thoughts and contributions. I am sorry you experienced water over the floorboards and glad it worked out for you. With the self-contained water detectors available nowadays there should be no reason to have water detection accomplished by a wet foot.
I think you are wise to start your engine to charge your batteries at the initial sign of flooding. The voltage drop can be impressive under bilge pump load and the volume of water moved out of the boat will decrease markedly with voltage drop.
I did not address in much detail de-watering a boat as it can be a complicated, boat dependent topic worthy of an article (book?) on its own. I have thought deeply about this on our 40 foot sailboat and have followed others in their explorations and believe there to be no definitive method that can be generally applied: all are compromises, some significant. There is no vessel I know of which emerges from the factory floor which is even close to being prepared to deal with a flooding situation.
I have followed the efforts of a number of skippers who have attempted to make an AC sump/trash submersible pump work. Some misgivings I have about the method you describe for your boat include the time necessary to get your submersible pump out of storage, get the discharge hose out where it goes overboard and tie it down or it will flail about, plug the unit in and start the inverter (the DC to AC converter). That alone could take a bit of time and time is of the essence in the event of flooding. Every second of a significant leak makes the leak more difficult to find and finding the leak is the first priority as no pumps (on our recreational vessels) will keep up with a significant leak.
My other hesitation revolves around the need for you to be close at hand to 220 AC in a chaotic situation where you will be wet and sticking body parts in wet places to find the leak. I would urge you, at minimum, to make an AC pump a permanent install, hose permanently installed overboard and the electrical inspected by a marine electrician.
Better, in my mind, to stick with DC pumps, again permanently installed. Rule makes some big pumps that move a lot of water. If room, install 2. The idea being that you are buying time to find the leak. More volume is certainly better, but having something you just flick a switch to start the pump(s) and then quickly begininspecting for the leak seems to maximize the chances of finding of the leak.

My best, Dick Stevenson, s/v Alchemy, Harwich, England
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Strategy for a Flooding Vessel 1 year 7 months ago #2445

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Hello Dick,

Good thoughts. My bilge is very shallow, so I cannot install the pump permanently, it just wouldn't fit. So this is indeed a 2nd best option. I do however have the pump including hose fopr grabs ready dor use.
Same goes for the bigger Rule pumps, they do not fit under the floor...
I guess it would be possible to find another 12V high capacity pump that would fit, with a hose in the bilge and the pump in another place.

Best regards,

Erik Snel, sy Dutch Rose - Lemmer, NL
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