This is a post from the Society for the Prevention of Cruelty to Dories. One of the biggest and most tragic mistakes a boat owner can make–right up there with never using the boat, forgetting to tie it to shore, or taking the boat somewhere far, far beyond your abilities–is simply inappropriate storage when not on the river. Dories and drift boats take up more space than an enthusiastic boat purchaser or builder might think. They’ll happily eat an entire garage, much to the dismay of a boat owner’s friend. The simple solution might be to just park it outside with a tarp over it.

Wrong.

Tarps kill boats.

Even expensive custom tarps can kill boats.

Here’s the problem. As much as your boat looks happy with a shiny new tarp stretched over it, a few things begin to happen. First, the tarp is in contact with the gunwale, and it inevitably begins to sag, just a little at first, to the inboard side of the gunwale. Maybe that one early snowstorm stretched the tarp a little. You didn’t notice. The tarp is shiny and it’s holiday season. Water pools. Just a little at first. And the “waterproof” tarp lets a bit of water through into the boat. Humidity rises beneath the tarp, which has sealed itself against the gunwales. Water vapor condenses on the inside of the tarp and creates a fungal nirvana between the tarp and gunwale. Mildew starts. Wood gets discolored. Rot follows.

Meanwhile water begins to pool in the boat and things grow there. Mildew, rot, and perhaps even small creatures set up shop. As temperature falls, the water, which has seeped into the wood, freezes and thaws, freezes and thaws. Paint peels off. Plywood starts cracking. Joints suffer and think about failing. Water and its fungal friends find their way deeper into the structure of the boat.

You can see where this is going.

As boatbuilders and repairers, we have really seen where it goes. Here’s a photo from a sad Doryak owner who had no real reason to think that two tarps would certainly protect the boat. A springtime unveiling revealed a different story. And this is one of the lesser catastrophies brought on by tarps.

Perhaps a diagram will make the problem clearer:

Okay, so what is a dirtbag broke boatowner to do? Ministorage or  new building costs are prohibitive. Here’s a very cheap and effective way we have found to protect your boat baby during those unfortunate times of non-use.

Step One
Get the boat up out of the dirt on blocks, rocks, or whatever.
Get a 2×4 as long as the boat and make a couple quick braces to hold it vertically along the center of the boat
Make a couple side-supports out of scraps that go from your new ridgepole to a few inches beyond the gunwale.

Step Two
Get a sheet or two of half-inch sheathing plywood or OSB (oriented strand board) and screw them to the ridgepole and side braces (don’t screw it to the boat!), letting the plywood overhang the gunwales. The side braces will hold the plywood up enough to allow air circulation between the gunwales and the new roof.
Saw off the perimeter of the new roof a few inches beyond the gunwale. You now have a rigid roof with air circulation beneath it.

 

Step Three
Now—and not a moment before—NOW—you can cover the new little roof with a tarp. Secure the tarp, but don’t occlude air ventilation benath the roof. Keep an eye on the tarp for deterioration due to UV, wind, and general detrioration. As long as it remains relatively waterproof, the roof will not allow pooling or condensation, and the subsequent disastrous disintigration of your lovely boat. Air will circulate beneath the roof and prevent moisture build-up.

Note: Turning the boat upside down on sawhorses is a distant second. Water and its friends will screw up the gunwales from the gunwale’s underside. Tarping it will still trap moisture between the boat and the “impervious” floor and do its level best to deteriorate your boat.

Whatever you do to protect your boat, think about the many ways water and moisture will outsmart you. Squirrels are amazingly clever about outguessing you. Water and rot are way smarter. And you don’t want Dory Protective Services to come take custody of your boat.