Deck Leak Dodge

By Tom Neale, 7/29/2004


Tom Neale's logs have a new name and home on BoatUS Magazine. We know Tom has a loyal and devoted readership, so we wanted to share his tips and insights with an even bigger audience! For the latest articles, click here for Onboard With Tom Neale.

Deck leaks are like dust mites. Every body’s got ’em. No matter how rich and powerful you are, no matter how small a boat or fancy a yacht you have, it’s gonna have deck leaks. That trickle may come through a screw hole, it may come around a port hole, it may come around a hatch hole…heck, on my boat it wouldn’t surprise me if it came through a pot hole. The one thing for sure is that it’s going to come.

We all love hearing the pitter patter of rain on the deck at night. Feeling those tiny splashes of fresh water hitting your face is another matter. When I first started cruising, all I’d have to do would be to take my sleeping bag up from the deck and crawl in under my tent. I’m much better off now. I’ve got a bigger boat. I don’t have to go below when I feel the tiny splashes. I’m already there.

Modern fiberglass boats haven’t improved the situation. With a good ol’ wooden boat, all you had to do was watch the drip and you’d have a fair idea of where it came in. If you didn’t find out soon, no big deal. The wood planking or plywood decks would quickly rot away, as would any ambiguity as to its source. Now we’ve got things like plastic liners that let those drips run for miles before they make it to your face. A splash on the head while you’re in the head could have come from a leak over the galley on the other end of the boat—and it might have taken fifteen minutes for it to find that hole in the overhead over your head.

But it gets worse. Once you figure out where the water is dripping from the underside of the deck onto that plastic liner, you’ve got to figure out where the water came through the top side of the deck. Modern decks have all sorts of stuff like balsa and foam sandwiched between two layers of glass. So when the water runs through the top layer of the deck, it’s got lots of time to decide where it wants to come out of the bottom side—and this is before it even starts thinking about hiking around on that plastic liner.

Deck Leak Deliverance

Whether you have a runabout with decks around the sides or a full blown yacht, deck leaks can range from bothersome to extremely dangerous. Here are some special tricks for dealing with and fixing deck leaks.

Finding the Fickle Trickle

If you can’t locate the source of a leak, there is a trick that will almost always find it. All it takes is two people and a hose. First study the overhead layout around the area where the water is coming through below. Check out things like slope of deck around the area where you’re actually seeing the water below decks. Look for things like indentations in the head liner. Sometimes the manufacturer will mold in an indentation for stiffening, but this can also make a great little channel for water to run. Look out the portholes, if there are any nearby, to see what sources may be relevant on deck. These would include anything that pierces the deck. Stanchions and cleats are obvious, but also consider things like fuel and water filling ports and through deck wiring runs. When you’re looking out the porthole observe the slant in the deck. Remember that drips will often run down under the deck, clinging to its underside because of surface tension, before dropping off onto a liner to resume the journey.

Click Here for More Tips

There are various tried and true methods of dealing with deck leaks. I prefer the technical approach: placing pots and pans in the spot of choice. This, to be done successfully, takes a lot of figuring. First, you have to figure out where the deck leaks are going to drip next. Then you have to figure out the size of the pot for the size of the leak. Then you have to figure out when to wake up and empty the pot. And above all, you have to figure out what you’re going to cook in on rainy days.
Any solution starts with the Leak Location Factor. Some locations are easy to guess. They allow you the benefit of instant awareness. These include that spot right between your eyes when you’re asleep in the middle of the night, the middle of the page of the book you’re reading, and the delete key on your laptop while you’re typing. Some of the more insidious deck leaks keep you in suspense, not letting you know until much later, at times that you not only really don’t want to know, but also can do little about it. The first that comes to mind is the leak over the roll of toilet paper.

As with anything technical, you learn over the years. I used to think that after a while, I’d have the pots and pans routine squared away. All l had to do was let it rain, look for the wet spots, and mark them with an X. It turned out that there were two problems with this. The first was Mel. Her comments about my X’s can’t be repeated here. The second was drip migration. I found that all you have to do is add or remove fuel or water from your tanks, and that drip is going to move. Even a beam wind while you’re at a dock will result in drip migration. On some of my smaller boats, all I had to do was turn over in the bunk and the drip would move—usually with me. Finally I gave up and began the tactic of the Deck Leak Dodge. You just move over when you see one coming so that the next one will miss you.

Deck leaks, more than anything else, stimulate that age old debate as to whether it’s better to have a big boat or a little boat. To me, the answer seems obvious. The bigger boat is better because it’s easier to open up an umbrella below decks. However the issue is more complicated. Bigger boats have more places for decks to leak, but smaller boats have less room to jump around in when you’re trying to move out of the way. It’s like that age old question of whether you’d rather be attacked by a herd of elephants in a football field or a couple of elephants in a house. The uninitiated will ask, “Why don’t you just fix them?” That’s easier said than done. Fixing deck leaks on an old boat (and some new ones) is like killing mosquitoes in the bayou. You might stem the tide in one hole, but there’s always going to be another.

And some things you just can’t fix. One of my favorite boats (I’ve had a couple dozen favorite boats) was a Glaspar Seafair Sedan. Its little cabin had sliding windows on each side. Spray and rain would slide through between the panes like water sliding down a mountainside. I thought about caulking them closed, but I couldn’t decide which was better: being wet or being hot. So finally I came up with a solution. Never go fast in rough water, never go out in the rain, and never lie down in the bunks underneath the windows when you do either of the above.

But after many years of cruising, we’ve come up with the perfect solution. It compensates for varying angles of heal and rolling, it automatically adjusts for boat movement or horizontal realignment, it muffles the drip drop cacophony, it negates the need for constant jumping around (if not for ducking), it’s environmentally correct, it even greatly diminishes the need for emptying pots. I call it The Rainforest Solution. A few of the less inspired people who’ve been aboard call it, “hundreds of hanging potted plants.”

Copyright 2004-2005 Tom Neale