Winterize Your Boat
50 states, which would you guess had the most freeze-related claims? Wisconsin?
Maine? Michigan? Minnesota? Guess again. An examination of the BoatUS Marine
Insurance claim files found that balmy California had more winterizing claims
than any other state, including any of the “deep freeze” states. While winters
may be much colder in the deep-freeze states, the bitter temperatures are a fact
of life and preparations for winter are taken very seriously. But in the more
temperate states, like California, Florida, Texas, Louisiana, Alabama, and
Georgia, winter tends to be relatively comfortable in most areas with only an
occasional cold spell. And if the forecasts aren’t taken seriously, they can do
a lot of damage.
In some parts of the country, where winter means several months of bitterly cold
weather, storing boats ashore is the norm. In warmer climates, however, ice and
snow may occur infrequently, and the choice between storage ashore and storage
in the water is open to discussion.
Storage in the water means you might get a jump on the boating season next
spring. On the other hand, boats stored ashore (on high ground) won’t sink. If
you have a choice, storage ashore is a safer bet. Storage ashore may also be
less expensive over the life of a boat, since a hull surrounded by air for
several months each winter is less likely to develop blisters than a hull that
remains in the water. These blisters, the fiberglass equivalent of rot, occur on
many boats when water soaks into the laminate below the waterline.
One note of caution: The vast majority of the claims in temperate states
involved boats that were being stored ashore. Since water retains heat longer
than air, boats surrounded by air are more vulnerable to a sudden freeze than
boats surrounded by water. Even a brief cold spell that lasts only a night or
two can do considerable damage. In temperate states, boat owners must winterize
engines and freshwater systems, especially when boats are stored ashore. In deep
freeze states, boats stored ashore must be winterized earlier than boats stored
in the water.
Storage in the Water
This boat in Maryland sank when it’s plastic thru-hull was shoved underwater by
the weight of the snow. the intake was broken by ice (the surveyor who inspected
the damage suspected that it was already cracked) and water flowed into the boat
If the boat must be left in the water, the thru-hulls have to be protected by
closing all seacocks and gate valves. Leaving a thru-hull unprotected over the
winter is like going on an extended vacation and leaving your home’s front door
open. Failure to close thru-hulls is a major cause of loss in the BoatUS
insurance program. In a recent study of 40 winter-related claims, seacocks or
gate valves left open caused or contributed to the sinking of seven of the boats
in the sample group. It should be noted that raising and refurbishing a boat
that sinks, even at a dock, is a daunting job that can keep the boat in the
repair yard for many weeks over the spring and summer. Whenever a boat is stored
in the water over the winter, all thru-hulls, with the exception of the ones for
cockpit drains, must be closed or it could be on the bottom next spring. And all
thru-hulls, especially the ones for the cockpit drains, must be double-clamped
with stainless steel hose clamps at each end. This is critical. When water
freezes it expands and will lift a poorly secured hose off of a fitting. The
hose itself is also important. Lightweight hose and PVC tubing can rupture or
crack. Use only a heavily reinforced hose, especially at cockpit drains.
If your boat has thru-hulls below the waterline that can’t be closed, either
because they are mechanically frozen open or have broken (typical with gate
valves, which is why they are not recommended), it should be stored ashore for
Seacocks are closed by moving the handle down so that the handle is parallel
to the hull. Gate valves are closed by turning the wheel clockwise. After
the seacock or gate valve has been closed, remove the hose so that it drains
and then use an absorbent cloth or turkey baster to eliminate any residual
water, which can freeze and crack the nipple. (Taking off the hose also
assures you that the valve has closed properly.) Reinstall the hose
immediately and secure the two clamps.
It should be noted that thru-hulls above the waterline are not required to have
seacocks and most don’t. That doesn’t mean that these thru-hulls aren’t
vulnerable. Ordinary plastic thru-hulls deteriorate in sunlight and have been
broken when they were shoved underwater by the weight of snow and ice in the
cockpit, which then sinks the boat. Plastic thru-hulls near the waterline are
especially vulnerable and should be replaced with bronze or Marelon (the latter
is the only type of plastic approved for marine use by U.L.).
With a winterizing contract, make sure that everything is spelled out. Does the
contract specify covering the boat or winterizing the head? How about closing
“I Thought the Yard Would Take Care of That!”
A casual agreement to take care of the boat, or worse, an assumption that a
marina or boatyard automatically protects boats from an unexpected freeze can
have chilling results:
Claim #920726. The skipper was seriously ill, so he called the boatyard and
casually asked if they could winterize his houseboat. No problem! The boat was
hauled and blocked. The engine’s cooling system was drained and non-toxic
anti-freeze flushed throughout the freshwater system. Unfortunately, an
expensive winter cover that had been stored below was left untouched in a locker
and the boat was left to endure the harsh Minnesota winter au natural.
Engines don’t like to be idle, even for three or four months over the winter.
BoatUS Marine Insurance claim files contain many stories of engines that froze
and failed after skippers failed to winterize their engine properly. Generally,
engine blocks that freeze and crack are not covered by a boat’s insurance
But even if the engine makes it through the winter, a half-hearted winterizing
effort will come back to haunt you as the engine gets older and wears out
prematurely. Unless it is winterized properly, moisture, acids and corrosion
will continue unabated. Winterizing the engine is one job that is truly
critical; follow the steps below and consult your manual for specifics.
Most marinas are like floating ghost towns over the winter, with little to deter
prowlers. Electronics and other valuables that can be dismounted should be taken
home for safekeeping. If you have an EPIRB, make sure it won’t be activated
Besides electronics, all flammables—spare cooking fuels, charcoal, paints,
thinners, and varnish—should be stored ashore, preferably in a tool shed away
from the house. All are fire hazards. Portable propane canisters should never be
stored below on a boat, even during the season, as the canisters can rust and
leak. Leave at least one fully charged fire extinguisher in clear sight.
Take home all food stuffs, including canned and bottled goods. Bunk cushions
should be propped up, or better yet, taken home. Open various locker doors,
hatches, ice box lids, etc., to circulate air and inhibit mildew. Metal zippers
on cushions will benefit from a few squirts of a light lubricating oil.
In addition to ensuring cockpit drains are clear, having a boat cover can keep
the cockpit from filling with ice and snow and dragging down the boat.
If your boat could talk, it would ask—perhaps plead—for a winter storage cover.
Winter covers, typically canvas or synthetic, are a terrific benefit to your
boat’s gelcoat and general well-being. Canvas covers tend to last longer but are
also more expensive than their synthetic counterparts.
With any cover, a frame, either wood or aluminum, should be used to circulate
air and prevent pooling on the cover. Merely draping an old tarp over a cabin
may do more harm than good.
Shrink wrapping, a technique borrowed from grocery and department store
packagers, is being used by some boatyards to keep boats dry over the winter.
With shrink wrapping, heat is applied to a thin plastic so fits snugly over a
plastic frame. At the end of the season the entire cover, including the frame,
is disposed of. While shrink wrapping is very effective at keeping moisture out,
it will also trap moisture inside and create horrendous mildew problems if vents
aren’t used along the entire length of the cover. Another problem: Cabins and
decks painted with two-part polyurethane paints may peel or bubble. Vents should
be used along the entire length of the cover. Inserting a series of foam pads
between the hull and cover also allows condensation to escape.
Finally, some skippers mistakenly believe that biminis, which shield the crew
from glaring sun will also protect the boat from freezing rain and snow. Quite
the contrary; expensive biminis tend to get ripped apart or aged prematurely
while doing absolutely nothing to protect the boat. Biminis should be stowed
below, or better yet, taken home and cleaned over the winter.
Reprinted with permission from Seaworthy, the BoatU.S. Marine Insurance and
Damage Avoidance Report. You can visit www.boatus.com/seaworthy/winter/ for the
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(c) 2006 by Northern Breezes, Inc. All information contained within is
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