Some tips for winterizing your Lagoon

It is approaching, the weather is getting warmer… Spring will be here in less than one month. To help you do things the right way, the Lagoon delivery team gives you some tips for the new season and to be complete.

March 3, 2023

It is approaching, the weather is getting warmer… Spring will be here in less than one month. To help you do things the right way, the Lagoon delivery team gives you some tips for the new season and to be complete, what you should have done for the winterization. Indeed most of you will soon start the season but others will be ending it, depending which hemisphere you are from! Thanks to Philippe and Nicolas for writing this post.

This process is right for boats that you closed for the winter without watch.



  • Open all taps and shower.
  • Switch on the fresh water pumps until the tanks are empty (hot water also).
  • Switch off the pumps.
  • Leave the taps open.
  • Disconnect the pipes from the pumps.
  • Empty the fresh or seawater pumps of the toilets by closing the seacock.
  • Check that the holding tanks are empty.
  • Put vaseline with a paintbrush on the seacocks and through hull fittings to protect them.
  • Empty and dry all the sumps (hulls, engines, anchor locker…).
  • Leave the drains of the different equipment (AC, fridge…) open.
  • Bleed the seawater cold circuit pump of the AC (or glycol treatment depending your AC model).
  • Rinse the membranes of the watermaker and do the winterization treatment (depending of the model you have).


  • Reconnect the pipes to the pumps.
  • Fill the water tanks.
  • Start the pumps keeping the taps open.
  • Wait until the water flows properly through all of them, close them one by one.
  • Make sure the pump shuts down correctly.
  • If necessary, reopen taps to remove air from the system.
  • Do not forget to open all the seacocks closed for winterization.
  • For toilets: Pour a small coffee cup of cooking oil and then activate the pump (manual or electric) This will prevent the joints from tearing when returned to service.



  • Close the seawater suction seacock.
  • Open the seawater filter.
  • Start the engine / genset and simultaneously pour “four season” seawater coolant and biodegradable antifreeze into the filter until they come out from the exhaust.
  • Stop the motor / genset.
  • Close the seawater filter.
  • Refuel your tanks to prevent condensation, antibacterial therapy may be appropriate if you have doubts about the quality of fuel on board.
  • Spray a little WD 40 (it’s water repellent) on electrical motor connectors.


  • Open the suction seawater seacock.
  • Make sure the seawater filter is properly closed.
  • Start the engine and ensure that the exhaust spits correctly.
  • If the boat is outside, remove the propeller and or grease the mechanical parts of the folding propeller.



  • Remove and dry the sails before storing. If necessary, send them to your sail maker for maintenance.
  • Ease all the ropes which used to stay in tension and prevent them from knocking with the wind.
  • Place the boom on a fender to ease the topping lift and secure it to prevent it from moving.
  • If possible, replace the halyards and other running rigging parts of the mast by messengers.
  • Tidy up all the ropes and hang them to the mast foot for those that cannot be removed.
  • Put Teflon or equivalent spray on the various cars.
  • Remove outdoor protection (bimini, etc.).
  • Dismantle the anemovane to avoid the masthead serving as a perch for birds.
  • To be perfect: locks, chain plates, ends of lifeline, and other metal stuff  can be coated with petroleum jelly (which rinses off very easily).
  • Remove the winch drums and spray WD 40. Be careful: no grease! It freezes.
  • The blocks do not require special treatment. The cover is a plus.
  • Small winch covers will be welcome.
  • Protect hatches.
  • Remove the chain tension on the windlass, and rinse the chain and anchor in freshwater.



  • Larger vessels require constant monitoring or regular passage on board: in this case and only in this case keep the batteries charging, keep electronics on.
  • Isolate engine batteries, genset and bow thruster.
  • Do not unplug the bilge pumps!
  • If no monitoring, also isolate the batteries from their consumer services.



  • Open the doors of fridge.
  • Put the mattresses vertical.
  • If possible, leave open or ventilate any “closed space” to prevent condensation.
  • Remove the steering wheel (without losing the cotter pin!) and put vaseline on the cone for fixing the steering wheel.
  • Spray WD 40 or vaseline on different padlocks and locker hinges.


Make a check list of operations carried out for the winter to remember to re-open the valves closed for the occasion. Do not hesitate to contact your local dealer for more equipment info (air conditioning, water maker, genset, engine…).

  • Avoid the use of grease (except for the propeller), prefer vaseline and WD40 (except plastic).
  • Encourage ventilation.
  • Change the engines and generator oil and do your annual maintenance during this period or just before winter.