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Getting Your Boat Through A Storm

Important work must be done when severe winter weather approaches. Here are action items to boost your boat's chances of coming through unscathed.

Snow-covered boats at the marina

Photo: Lindenthaler

Our BoatUS Marine Insurance claims files indicate that expensive and time-consuming repairs are ahead for boaters unprepared for winter storms. Owners of boats located in northern regions (where annual winterization is a fact of life) will be a step ahead of their southerly brethren, as most of the basics will have already been completed. Owners of boats stored in a wet slip or outside on a trailer will also have different concerns than owners whose boats are hauled or stored ashore at a boatyard or inside a garage.

Way Down South

It's no surprise that when freezing temps blast an area where annual winterization isn't the norm, many damage claims are sure to follow. If your winter storm-prep plan consists of hanging a garage drop light in the engine compartment and calling it good, you may want to beef it up with some of the following tasks.

Engines: Because the engine is likely the most expensive piece of gear you'll have aboard, proper engine winterization is crucial. From cracked blocks to fractured manifolds and risers, engines are particularly susceptible to costly freeze damage. Review your engine manual so you correctly complete all manufacturer-recommended steps for protection against freezing weather.

Cracked block

Freeze damage from storms can lead to a cracked engine block, as seen here. Follow manufacturer guidelines for properly winterizing your engine to prevent costly repairs. (Photo: BoatUS Files)

If you have an open (raw-water) cooling system, drain it thoroughly, paying particular attention to low spots or other areas where water could be trapped. For closed systems (freshwater), drain the open side completely or fill with antifreeze, then check the strength and level of antifreeze in the reservoir. If you have a generator, follow the same basic recommendations listed above, plus any special items called out by the unit's manual or required by your particular installation.

Freshwater System: Such a system is extremely prone to freeze damage, resulting in cracked fittings, split hoses, and worse. Drain the entire freshwater system (including the head, galley, and icemakers) and/or add a solution of nontoxic antifreeze for potable water. Draining eliminates the need to flush the system of antifreeze afterward, but be sure to remove all water from the system (inside pumps, low points in the hose runs) to prevent freeze damage. Using low-pressure compressed air — or even lung power — to purge the lines works well for this. You'll also want to drain the water heater and any gray-water sumps (shower). Check the manuals regarding antifreeze for all applications; some components may be damaged by what you use.

Sanitation System: Properly dump and clean portable, self-contained toilets. Flush and completely pump out permanently installed toilets and holding tanks. Follow the manufacturer's instructions for additional winterization guidance.

Air-conditioning System: Drain or purge all water, including the raw-water strainer. An alternative is to flush the system with antifreeze; just be sure the entire system is protected (the seacock, strainer, pump, and all downstream plumbing).

Canvas: Remove all canvas (including bimini tops and curtains) where appropriate and store ashore. Don't wait until it's too cold to do this, as the material may crack or be too stiff. Ensure that any canvas or covers left in place are robust enough to withstand high winds, ice, and snow. In many parts of the country, storm winds exceed what a bimini top is designed to endure.

Unfurled sails
Ideally, sails should be removed and stowed ashore before a
storm. If that's not possible, however, they should be secured
to prevent unfurling and flogging. (Photo: BoatUS)

Sails: Remove and stow sails ashore to prevent damage. If you can't, securely lash them in place to prevent unfurling/flogging. A flogging sail can damage not only your rig but also your neighbor's.

Hauled/Stored Ashore: Check the condition of cradles, support blocks, and jackstands. Ensure that each is positioned properly and that your boat is properly supported.

Place strong, stable plywood sheets under jackstand bases, and ensure that safety chains are in use. Boats can rock in high winds, causing unchained jackstands to move and allowing the boat to fall. Make sure your boat is level, to promote proper drainage. Never tie covers to jackstands or support blocks. Flapping canvas can yank them out in high winds, causing the boat to topple over. Remove all bilge drain plugs.

Boats Stored On A Trailer: Move your boat to the safest location possible (e.g., indoors, or away from flood-prone areas). Park them away from trees to avoid scupper-clogging leaves as well as damage from falling tree branches. Clean the cockpit of debris, such as leaves, that could clog scupper drains, remove all bilge drain plugs, and ensure that all scupper drain seacocks are open and draining properly. Unstep the mast of trailerable sailboats to reduce windage.

Boats Stored In The Water: Check docklines for wear; replace iffy ones. Double up lines where possible. Inspect dock cleats and hardware. If questionable, consider tying lines directly to pilings. Center your boat in the slip using long docklines and spring lines to account for higher-than-normal tides and to keep the boat away from the dock; this prevents the boat from banging into the dock or even becoming trapped beneath it. If your pilings are appropriate, consider using TideMinders, which allow lines to roll up and down pilings.

Add chafe protection to lines, and inspect chocks and fairleads for damage or sharp edges that could damage docklines. During a big blow, I've seen the sharp edges of a damaged chock saw through a new line in a matter of minutes. Adjust fender placement and add additional ones as needed. This is one area where bigger is better. Two or three well-placed larger fenders will prevent dock damage better than five undersized ones.

Verify the proper operation of all bilge pumps, automatic float switches, and bilge alarms — you do have a bilge alarm, right? Keep seacocks for cockpit drains open. Plug exhaust ports to prevent possible flooding should snow pile up and force them underwater. Be sure to remove them before using the vessel. Tie off or secure steering wheels and tillers.

Boats stored in the water are vulnerable to damage from water-level extremes, strong winds, and snow. Check on your boat before, during (if it's possible to do so safely), and after the storm.

If your boat is under a covered dock, note that our claims files are rife with boats that were damaged when snow load exceeded build strength and roofs collapsed. Move your boat to a safer slip. Better yet, bring it ashore.

Boats On A Lift: Check the condition of lift wires, chains, and fittings. Clean the cockpit of debris, such as leaves, that could clog scupper drains; claims for broken lifts due to boats overloaded with water occur every winter. Remove the bilge drain plugs so deluges can empty. Ensure that all scupper drain seacocks are open and that they all drain properly. Check that hoses are in good shape and properly connected. Consider removing your boat from the lift and storing it ashore, say on a trailer.

Up North

Like death and taxes, boat winterization in colder climes is a fact of life, for it's a certainty that if it isn't completed in the fall, it will surely result in damaged systems and lighter wallets come spring.

We'll assume that you've completed the general boat-system preps listed above and are a step ahead of a winter storm. But don't get complacent. Visit your boat well before the storm hits to make sure all is ready and as you left it when tucking her in for her winter nap. In addition to the steps outlined above for your Southern neighbors, check the following:

Boats Hauled/Stored Ashore: Check your winter cover, whether canvas or shrink-wrap. Ensure that it's properly secured with no loose ends, rips, or tears. Winter storms in the North tend to have higher winds, so make sure jackstands are secure. Loose covers, especially those with grommets, can do some damage to that pretty hull. Make sure they're tied down properly.

Boats Stored On A Trailer: Check winter covers, verifying that each is in good condition and properly secured. Trailered boats, without the benefit of sitting in temperature-moderating water, feel the cold before their docked brethren, so double-check that all systems have been properly winterized. High winds can topple trees, so choose a storage area out of danger.

Boats Stored In The Water: In many northern locations, strong winds can pile up water and significantly raise and lower water levels beyond the norm. Make sure that your dock-tying strategy takes these extremes in mind. Heavy snow can weigh down a boat until the scuppers are forced under and backflow, sinking the boat. If you don't have a cover, ensure that drains are free, and check on your boat as soon after the storm as possible. After a storm, temperatures often plummet, and your winterizing will be tested. Double-check that any place in your boat that holds water has been drained or filled with antifreeze rated for at least the coldest temperatures that are likely to occur.

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Frank Lanier

Contributing Editor, BoatUS Magazine

Capt. Frank Lanier is a SAMS Accredited Marine Surveyor with more than 40 years of experience in the marine and diving industries. He’s also an author, public speaker, and multiple award-winning journalist whose articles on boat maintenance, repair, and seamanship appear regularly in numerous marine publications worldwide. He can be reached via his YouTube channel “Everything Boats with Capt. Frank Lanier” and website