Seacock Locations and Diagram

Here’s something that is taken directly from Captain John’s Sailing Tip of the Week. Something so silly and obvious, but we all get lazy don’t we…

We have a primer for “seacock locations” on our Pre-Departure Checklist on the Links page, but we’ll add a little more context to it from now on with the great advice below. In short, make sure everyone knows what you do, and at 3am in a storm a picture is a great help.


Let’s take a basic sailing emergency that requires training. Flooding. Not so common you say? Quite so on a boat that has no through-hulls. But, how many production boats will you find with less than 6-8 holes near or below the waterline? Cruising sailboats are littered with them. If you drill a hole below the waterline and set sail, then you are at risk of flooding.

Now, this does not constitute the need to panic, but it does elevate your risk of flooding. Every member of your crew or your partner must know the basics of flooding damage control. Without electric bilge pumps. Emphasis–without electrical bilge pumps. The basics are simple.

Ask ten crew the first step in flooding damage control. How many will say locate the source and shut off the seacock? Ask the same ten crew to go through the boat and point out the seacocks. They are welcome to use a seacock diagram as they do. Watch the jaws drop. On many boats the response will be something like this: “What’s a seacock diagram?”

So, how can you have an effective plan to deal with flooding if your sailing crew or partner does not know the location of the seacocks aboard? Again, through-hull locations need not be memorized. But the crew need to be able to locate each through-hull with a simple seacock diagram. Not in their head. A clear, easy-to-read seacock diagram with labels.

What’s my #1 first goal when I step aboard a boat as volunteer crew or as skipper? Go through the boat from bow to stern and find each seacock. The boat may or may not have a seacock diagram.

If not, I lash a piece of paper to a clipboard, grab a pen and flashlight and start at the bow and move aft. Open lockers, lids, floorboards, covers and locate every single seacock. It’s a pain in the butt. It’s tough to find those through-hulls jammed, crammed and hidden in crazy nooks and crannies.

Your knuckles can get dinged. And you’ll be dirty and sweaty at the end of the exercise. And you will find some seacocks that are frozen shut from lack of exercise. So you have to work to unfreeze a handle frozen from years of disuse. A light tap with a hammer or mallet often does the trick.

Seacock familiarity isn’t pleasant or fun. But one night when sailing along the coast or offshore with water pouring in, this simple exercise could save your boat from sinking. Or save another skipper’s boat if you are volunteer crew aboard.

Owners or skippers can be a pain in the butt too. I’ve had more than one skipper tell me “don’t worry about it”. Say what? Once you cast off for sea, we are out there. Sail with another skipper and you place your life in his or her hands. You have to be “worried about it”. This is no time or place to accept compromise.

Another point is the emphasis on so-called safety equipment that includes life rafts, EPIRBs and other high-tech gadgetry. I could not care less if a skipper carries those contraptions aboard. They are nice to haves. Sure, they are required by racing committees. But they are not a substitute for training or basic, common-sense, grey-matter safety-at-sea seamanship.

None of those items will stop flooding water from pouring in through a one inch hole one foot below the waterline at a rate of almost 1,200 gallons per hour at 0200 in the AM when you are 100 miles offshore.

A seacock will do that. Sure, there are other methods to control flooding, but the absolute basics begin with a simple seacock diagram. Click here for a free one you can print off right now => Seacock Diagram

Plot the through-hulls based on their location relative to the centerline (dotted line on diagram) and that third of the boat where they reside (click on link above to see diagram).

When you make the final diagram for posting in your cabin, make sure that it’s “crew friendly”. That’s super important. Create a diagram so simple and so clear that even the greenest crew member aboard can follow it. In an emergency, there will be no time for explanations. Keep it drop-dead simple.  That will help lower the stress in a true flooding emergency.

Use these easy sailing tips to train your crew or partner on the location of your through hulls. This will give all hands aboard more confidence and peace of mind for safer sailing or cruising on the waters of the world.

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