Our boat had enjoyed indoor storage over the past few years with its previous owner. We knew that wasn’t an option for us and we wanted to bring the boat home for the winter anyway. With outdoor storage, though, comes the possibility of damage from water and ice. Here are some things to look out for, and how we covered our boat to minimize the chance of problems.

This catboat was carefully protected in the late fall, but winter storms eventually tore the cover loose.

Rainwater that froze split open this J/105 spreeader.

Burst Spreader
One wouldn’t think that a little rainwater inside an aluminum spreader could do too much harm. But when water freezes, it wants to expand about 10% and can blow apart more than just a plastic soda bottle. This J/105 spreader was left on a mast and angled downward a bit as it sat outside. Water got in and froze – an unpleasant surprise in the spring.

Frozen water dripped into this headfoil and eventually pushed it apart.

Split Headfoil
The owner of this boat was quite disappointed when he tried to put his jib on the headfoil for the first time last spring. At first, he (and everyone else) thought that the headfoil must have been damaged by the yard when the mast was stepped. A closer look revealed no marks or dents on the headfoil from impact, and the foil was bent open, not closed. The final verdict – this must have been a low spot in the headfoil as it sat outside on a rack. Enough water got inside to fill that area and once it froze, it bent the foil.

Cracked Stanchion Bases
At first glance, this stanchion base looks like it cracked when the stanchion was pulled inward, and that may be the case. But this boat had other bases with cracks in different positions. Since these bases are aluminum, they could have been weakened by galvanic corrosion from their stainless steel stanchions. Or, if rainwater filled the stanchions & bases and froze, it could have caused the cracking. Bill Seifert, in his book Offshore Sailing, recommends drilling small drain holes in all stanchion bases to prevent water from collecting there.

Once water gets into a cored deck, freeze/thaw cycles push the skins apart.

Deck Damage
These photos show cracks from water that froze inside balsa-cored decks—and just how much wet balsa core needed to be replaced. Without being able to see between the fiberglass layers, I can only speculate that repeated freeze/thaw cycles push the deck skins apart, open cracks in the surface, and open passages within the core for water to migrate even farther.

This simple cover is low-profile and keeps water off the deck, preventing ice problems.

Split Rudders
Rudders suffer the same fate as decks when water gets in through fittings or down the sides of a stainless steel rudder shaft. Cracks down the leading or trailing edge of a rudder are sure signs that water is splitting it apart. Whenever possible, it’s smart to remove rudders from boats stored outside and bring them inside for the winter. If that’s not possible, and rust streaks or cracks lead you to suspect you’ve got water in your rudder, drill a small drain hole at the bottom. (Just make sure you remember to fill it in the spring.)

Bungee cords allow the cover to move without ripping out the grommets.

A Simple Cover
We live in a windy spot (a former cornfield on a hill), and with the boat and its jack stands sitting on grass, I didn’t want to create a big shrink-wrapped tent over the boat that could become a boat-flipping spinnaker in a winter storm. The boat also has painted topsides, and shrinkwrap can hold moisture against painted surfaces which causes blistering. Finally, I don’t like the idea of using all that plastic, even if it gets recycled.

Our alternative was to use two heavy-duty black/silver tarps and plenty of rubber straps and line to lash them down to the deck. These individual tarps have been used for at least three previous winters on other boats, and they are still going strong.

The rubber straps (or bungee cords) are the key to the process. I learned this years ago from Guy Gurney, the sailing photographer, who brought his Star into my boatshop for repairs. He used a standard blue tarp to cover his boat, but swore by the use of bungee cords to tie it down - and his tarps didn’t rip, get loose, for flap around.

In our case, one tarp starts at the bow and reaches most of the way back to the companionway. The second one overlaps it by a few feet and extends to the transom. They don’t cover the stanchion bases or the toerails, but they keep the snow and ice off the rest of the deck. The rubber straps keep them tight without ripping the grommets out, and the lashing lines crisscross the deck between stanchion bases to keep the tarps down. Moveable cars and padeyes on the toerail make great adjustable anchors for the bungee. It was quick to install, keeps the water away from most deck fittings, and can be used again next year.

Editor's Note: This story is part of a series on buying a used J/35.

Paul Grimes is an engineer and marine surveyor living in Portsmouth, RI. For more information, visit the Grimes Yacht Services website.