As winter takes hold across the country, many boat owners wonder if their preparations are sufficient to withstand the harsh conditions of the winter months. Boat owners throughout the United States often store their boats over the winter, choosing to keep them at marinas and similar storage facilities. One of the biggest risks for boat owners during winter is the possibility that engines may freeze, causing significant damage or even total loss of the boat’s powerplant. Such damage is rarely covered by marina insurance, leaving boat owners on the hook for expensive repairs or replacement costs. In this guide, we’ll explore ways that boat owners can protect their valuable investments, no matter what severe winter weather comes their way. 

Winter Boat Storage: Risks of Freezing Damage

There are several different winter storage options for boaters. Marinas often provide more than one method of boat storage, including wet slips or moorings, outdoor dry docks, or covered indoor storage racks. Although storage methods may differ, freezing temperatures and accumulations of ice and snow can cause expensive damage, especially if boats are not winterized properly.

Damage from prolonged freezing temperatures can include:

  • Cracked engine blocks
  • Cracked or broken heat exchangers and oil coolers
  • Burst coolant lines
  • Cracked or burst water storage and holding tanks

Heavy accumulations of snow and ice on boats stored outside can lead to damage as well. Cockpit covers and decking have been known to collapse if snow is allowed to pile up. Water can get into small cracks or gaps in the deck, and when it freezes, it expands, causing damage that can be difficult and expensive to repair.

It is critical for marina operators to let their boating clients know that marina insurance may not cover damages caused by harsh winter weather. Boaters should ensure that their own insurance coverage is sufficient to protect against such damages – and more importantly, that boaters take the steps needed to winterize their vessels.

Winterizing Boat Engines

Preparing boat engines for winter’s freezing temperatures is a multi-step process. For boat engines that are raw freshwater- or saltwater-cooled, the procedure is the same, even though saltwater freezes at a slightly lower temperature than fresh water. Here are some great boat winterization tips to keep engines from becoming damaged:

  1. The first step is to drain any remaining water in the engine itself and any coolant lines that feed water to the engine.
  2. Next, it is a good idea to replace engine oil with a fresh supply. This removes any water that may be trapped in or mixed with the oil. Don’t forget to replace the oil filter when the oil change is completed. Some boaters also like to use engine fogging products to deposit a thin layer of protective oil in the engine cylinders, which can help them withstand freezing conditions.
  3. Stabilizing the fuel is a critical step that is often overlooked by boat owners. Fuel stabilization can be added to the tanks, then the tanks should be topped off with fresh fuel to prevent moisture from being absorbed.
  4. Water storage tanks and head holding tanks should be drained or pumped out to prevent damage. Many marinas offer pump-out services, but it is a good idea to take advantage of those services earlier in the season, as they may not be available over the winter.
  5. Investing in marine-grade antifreeze for antifreeze-cooled inboard engines is a good idea. These specially-formulated products can withstand temperatures down to -50 degrees Fahrenheit. Eco-friendly antifreeze products can also be added to water storage and holding tanks to prevent burst lines.
  6. Finally, investing in an engine block or engine compartment heater makes sense, especially for boaters in the northern states that expect to see prolonged below-freezing conditions. Engine heaters draw a lot of currents, so it is a good idea to ensure that shore power cables are in good shape before winter weather sets in. 

With these tips, boat owners can protect their vessels over the winter months and know that they’ll be ready when warm weather returns. Again, marina insurance may not cover damage related to freezing weather conditions, so boat owners should check with their own insurance companies for coverage options. 

About Merrimac Marine Insurance

At Merrimac Marine, we are dedicated to providing insurance for the marine industry to protect your clients’ business and assets. For more information about our products and programs, contact our specialists today at (800) 681-1998.