Log in links for this page

CZ-Tip - Boat Winterizing—Keep It Green

Find ways to get to, protect, and enjoy the coast with tips from the Massachusetts Office of Coastal Zone Management (CZM).

In colder climates, such as here in New England, boats are usually removed from the water for storage over the winter. It is important that vessels are properly prepared for storage to ensure that all parts and systems are protected from the weather and are not harmed from the lack of use. This process, referred to as winterizing or decommissioning, can impact the environment if not done properly. Oil may spill during an oil change, fuel can degrade if not stabilized, soaps and detergents can harm marine life, bottom paint can wash into the water during pressure washing, and boat sewage can pollute coastal waters if not disposed of properly. The following information gives specific tips to winterize your vessel in an environmentally sensitive manner.

Boat Hauling

The first step to most winterizing efforts is to get your boat out of the water. Here are some issues to consider before hauling your vessel.

  • Got Sewage? - Sewage holding tanks should be emptied before winter storage. If your marina/boatyard does not have a pumpout facility, see CZM's Massachusetts Pumpout Facilities web page for a list of coastal pumpout facilities for boat sewage.
  • Hull Cleaning - Washwater generated as a result of hull cleaning may contain pollutants that can harm coastal waters. If your boat needs to be pressure washed, check that your marina manages that wastewater properly, according to the requirements on CZM's Pressure Washing at Marinas web page. If doing it yourself, place a tarp below the boat to collect paint chips and debris. Also be sure to pressure wash away from any storm drains or waterbodies.
  • Clean Bilge - It is best to empty the bilge for winter storage to reduce the chance of a spill and to ensure that the bilge pump is not harmed by ice. Oily bilge water is a hazardous waste, so before emptying, place an oil absorbent pad/sock (available at marine supply stores) in the bilge to capture all oily waste, then have your marina pump out the clean water. If doing it yourself, use absorbents to remove all visible oil and pump bilge water onto the ground away from storm drains and water bodies. See CZM's Bilge Sock web page for details on absorbents.

Fuel and Oil

Fuel and oil degrade marine water quality and are toxic to humans and marine life. Proper winterizing is important to eliminate oil spills and ensure that fuel is stored properly. These simple steps can help you with fuel and oil winterizing.

  • Used Oil - Winterizing a boat's motor and outdrive can create a lot of waste oils. Be sure to carefully collect these fluids for your marina or municipal oil recycling program. Retailers are also required to accept used oil from customers for recycling. Always keep a supply of absorbent pads to handle drips/spills. Do not dispose of used oil in the trash, on the ground, down the drain, or down a storm drain. Check with your marina or municipality for information about proper disposal of these materials. The Massachusetts Department of Environmental Protection has a Safely Manage Hazardous Household Products web page that provides additional details.
  • Fuel System - Gasoline with 10 percent ethanol (E10) can cause fuel system problems, such as disintegration of fiberglass fuel tanks, the gumming up of fuel lines, and piston and valve failure. Ethanol can also absorb a lot of water, which collects in fuel tanks. This can make the fuel unusable. Proper preparation of the fuel system is critical to protect the vessel and fuel for winter storage. Boaters should follow engine manufacturer recommendations. In addition, BoatUS has prepared an article that provides advice on the use of fuel stabilizers, whether to leave the fuel tank full or empty, and other details about this issue.

Water Systems

It is important to properly winterize the engine cooling and drinking-water systems on vessels to ensure that engine blocks and plumbing do not freeze and crack. It is important to drain each system as much as possible. Be sure to fill each with non-toxic antifreeze. Never use automotive antifreeze (ethylene glycol), which is toxic to the environment and can cause serious illness if used in drinking-water systems.


When cleaning above the waterline, be sure to use an environmentally friendly soap (or water and elbow grease). See CZM's Get Your Home Squeaky Green-Clean for details.

Additional Information

Here are a few additional resources to explore.

Help Us Improve Mass.gov  with your feedback

Please do not include personal or contact information.