Please select your home edition
Edition
Rooster 2025

Use This Sailing Safety Tool in a Flooding Emergency!

by John Jamieson on 25 Jan 2013
Make a simple seacock diagram. Divide the hull into thirds lengthwise to represent the forward cabin, main cabin, and cockpit/stern area. Place a dotted line down the middle to represent the centreline. SW
The average sailing boat could have eight to twelve holes drilled below the waterline. These 'through-hulls' are used for heads, sink and shower drains, cockpit scupper drains, engine intake, instrument transducers, shaft exits and the rudder post. Each could be the source of a catastrophic ingress of water if they are not maintained. If the worst does happen, knowing precisely where they are and how to fix the problem quickly could save your boat.

Follow these easy steps to make sure your through-hulls do their job for peace-of-mind at the dock, at anchor, or when you're underway.

How to Avoid the Danger of Flooding
Most through-hulls are covered by a valve--called seacocks--with a handle that can be opened to allow sea water into the boat or shut to keep sea water out. Seacocks are the most important components beneath the waterline and need attention and care to prevent flooding. Check every handle on every seacock on every through-hull. Surveyors report time and again that they find frozen sea-cock handles on most every boat they inspect. You must be able to close any seacock with minimum effort.

Move the handle from open position (parallel to the hose) to closed position (perpendicular to the hose) and back to open. This exercises the seacock handle to keep corrosion at bay, and the handle lubricated. Open frozen seacock handles with a light tap from a hammer or mallet.

Examine the hoses at the top of each seacock. Replace hardened or cracked hoses right away. They are the number one cause of through-hull failure. Inspect the stainless clamps on each seacock hose. Replace rusted or corroded clamps. Double-clamp hoses on each side of a device or fitting. This adds extra security and peace-of-mind.

Insure that a tapered wooden plug gets lashed to the base of the seacock with easy-to-break twine. If a seacock hose fails, you can drive the plug into the seacock hole with a hammer or mallet as a temporary repair.

Mount a hammer or mallet nearby in brackets in a conspicuous location in the main cabin. Paint the handle day-glow orange or red. Add reflective tape strips to make it visible to a flashlight on the blackest night. Brief your sailing crew or partner. Instant accessibility could make a difference in keeping your boat afloat.

Inspect, clean, and lubricate every seacock once a year when you haul your boat. This gives you the perfect opportunity to find and fix problems. That way, you will have peace-of-mind that all of your through-hulls are in great shape for another sailing season.

Make a Simple Seacock Diagram
Make a Seacock Diagram for your boat (see illustration). You need to do this just once. If you add additional through hulls in the future, update your diagram. Post the completed diagram in the cabin so that all hands can see it.

Make another copy and insert it into your ship's papers notebook or briefcase. Spend a few minutes to go over the diagram with your crew so that they can locate any seacock aboard your boat within seconds.

1. Attach a piece of paper to a clipboard. Draw an outline of a hull (see illustration). Divide the diagram lengthwise into thirds as shown. These represent the forward cabin, main cabin, and cockpit/stern area. Make a dotted line down the center of the diagram from bow to stern to represent your boat's centreline. Strap a rubber band near the bottom of the clipboard to hold your diagram in place. Grab a pencil.

2. Start in the forward third of your boat (forward of the main cabin). Remove lockers, lids, or access covers to locate each seacock.

3. Plot small circles onto the diagram to indicate each seacock. Label each circle (head, shower, washdown hose, etc …) Note the dotted line down the centreline of the diagram. Seacocks should be plotted to the left, right, or along the centreline for faster access. Color code if desired (see illustration).

4. Include bilge cover plates. These can be difficult to locate in trying conditions because fine joinery work can make seams almost invisible.

5. Move to the midships section (main cabin); then to the aft section (cockpit and stern). Repeat the process. Print a second copy of the insert. Transfer your rough sketch onto the new insert so that it's neat and legible. Post it where all hands can see it day or night.

Note that not all through-hulls are covered by sea cocks. Include these locations on your diagram: shaft exit (where the propeller shaft exits the hull), rudder post location, fuel and water vents.

Use these easy sailing tips to keep your boat's 'gates to the sea' working to perfection--wherever in the world you choose to cruise!

John Jamieson (Captain John) with 25+ years of experience shows you the no-nonsense cruising skills you need for safer sailing worldwide. Visit his website at www.skippertips.com. Sign up for the Free, highly popular weekly 'Captain John's Sailing Tip-of-the-Week'. Discover how you can gain instant access to hundreds of sailing articles, videos, and e-Books!

Maritimo 2023 S-Series FOOTERsMRT AIS Man Overboard Beacons AUS / NZJeanneau Sun Odyssey 350

Related Articles

Rooster Sailing's 2025 Collection Just Dropped
From the redesigned Technical Shorts to the all-new SB2 Deck Trainers From the redesigned Technical Shorts to the all-new SB2 Deck Trainers, the 2025 collection has been developed with real sailors, for real conditions.
Posted today at 4:00 pm
Expanding horizons with West System Epoxy
Working on D-Class boats over the years sparked Jonathan Minnebo's love of sailing Returning to his roots, Jonathan Minnebo has broadened his sights from solely shipwright work to creating bespoke furniture and staircase design and installation.
Posted today at 6:54 am
2025 Santa Maria Cup in Annapolis, USA Day 2
Final four skippers emerge from a competitive qualifying double-round robin stage A thrilling second day of racing at the 2025 Santa Maria Cup saw the final four skippers emerge from a competitive qualifying double-round robin stage.
Posted today at 4:47 am
SailGP to Kick Off Summer in New York
With this Weekend's Mubadala New York Sail Grand Prix An unforgettable weekend of high-speed, close-to-shore racing and world-class entertainment will take place this weekend when the Mubadala New York Sail Grand Prix takes place in front of the most famous skyline in the world.
Posted on 5 Jun
Scandinavian Gold Cup at Sopot, Poland Day 1
A slow start with very little wind The Scandinavian Gold Cup opened Thursday in Sopot, Poland, with seven 5.5 Metres competing for this historic and iconic trophy that dates back to 1922. Unfortunately, there was not enough wind to even complete one race.
Posted on 5 Jun
49er, 49erFX and Nacra 17 Europeans Day 3
A six-hour bake on the water Veteran and multi-Olympic race officer Sulis was clear at the morning briefing, "Our priority is to get three races for the 49er so they can progress to the gold fleet."
Posted on 5 Jun
Galicia 52 Super Series Royal Cup Day 3
Platoon Aviation turn up the heat but don't dent American Magic Quantum Racing's lead After a disappointing first regatta of the season when they finished in an uncharacteristic last position in Saint-Tropez, the fortunes of the German flagged 2023 52 SUPER SERIES overall champions Platoon Aviation seem to have turned for the better.
Posted on 5 Jun
Diverse international fleet for 5th AEGEAN 600
The race start is a little over 1 month away In a sign that this newest of the world's 600-mile classic offshore races has reached maturity, organizers from the Hellenic Offshore Racing Club are pleased to announce yet another large international fleet will be assembled for the 2025 AEGEAN 600.
Posted on 5 Jun
America's Cup: Another sponsor signs for Italians
Luna Rossa has announced that Unipol has renewed its trust in the team Luna Rossa has announced that Unipol has renewed its trust in the team and will accompany it as an official sponsor for the duration of the 38th America's Cup.
Posted on 5 Jun
SailGP: Media Conference concludes in New York
Skippers speak ahead of the Mubadala New York Sail Grand Prix The media conference ahead of the Mubadala New York Sail Grand Prix has concluded, without any special points being revealed, save for Brazil lending a crew member to Germany.
Posted on 5 Jun