Winterizing a warm-weather yacht

Feb 13, 2018 by Guest Writer

By Capt. Rupert Lean

The megayacht industry rarely winterizes a yacht. Usually there are crew living on board or the yacht is sent south to warmer waters instead of completely shutting it down. This past summer, the owner of the 105-foot Palmer Johnson motor yacht that I was running as captain asked me what my thoughts were on winterizing the boat. I answered, “It would not be a good idea. But if that’s what you want, I would get it done.”

So when he decided to let the crew go, haul the vessel and winterize it on the hard at a Newport shipyard in New England with temperatures dropping to -20 to -40 Fahrenheit, I had to find a process to protect the vessel from freezing.

It was the end of one of the most beautiful summers in Newport, Rhode Island – one of the best I can remember. Newport was clearing out fast at the end of October, leaving the locals to enjoy their town in peace. The shipyard was full of very large sail yachts prepping for their trip south to the Caribbean, so I had to wait until Dec. 5 to haul and start the winterizing process on board the yacht. It started snowing three days later.

I followed a process that included making lists of all that needed to be done and what needed to be removed from the vessel, including adding a stabilizer to the fuel on board for safe storage.

The beginning of the winterization process: haul-out and water dump. Photo by Steve Figueiredo

First, we removed the vessel from the water and dumped all the fresh water from tanks, i.e. fresh, gray and black water. It is very important to have no standing water anywhere on the vessel, in or out on deck. Especially as this winterizing was not done in an enclosed shed, but on the hard in an area where the bottom paint might be worked on.

Once the vessel was pulled, it was heavily blocked to withstand winds in excess of 60 knots, which can occur in a New England winter. Next, we went round the vessel and opened all the sea strainer lids, and set more than 100 gallons of biodegradable antifreeze in 55-gallon drums on the ground outside the boat. We used hose pipe and a good pressure-switched pump to deliver antifreeze to each location around the vessel, including all plumbing loops and sea strainers.

The whole process was made easier by employing Nor East, a company that is set up to winterize boats. This was one of the largest “boats” this company had done. We had one person from Nor East and myself, as it takes a minimum of two people working together to make all this happen. It took us about four days to just secure the inside.

Getting coolant antifreeze to all the points was made simple by pressurizing the fresh water loop with the pump from the drum and opening every point around the vessel, from the highest to lowest points. We operated everything from toilets to windshield wipers, and didn’t forget the washing machine.

We bled all points until the pink coolant became visible. The engines and all salt water systems were started one by one, and at each sea strainer basket we filled the pump from the 55-gallon drums that free-flowed until we got pink discharge at the overboard outlets. We ran the main engines and generators one at a time; we needed to see pink coolant discharge for the mufflers, which is why 100-plus gallons is needed.

The to-do list included:
1. Freshwater tanks – open tank tops empty and clean.
2. Gray tank – empty and clean.
3. Black tank – empty and clean.
4. Air conditioning salt loop – flush with antifreeze and drain.
5. Air conditioning fresh water loop – just add straight coolant.
6. Freshwater lines, cold side – flush with antifreeze.
7. Freshwater lines, hot side – flush with antifreeze after draining hot water tank.
8. Toilet bowls – antifreeze.
9. Sink drains  –  antifreeze via running tapes when flushing systems.
10. Bilges – vacuum dry, check for standing water.
11. Service all pumps, run coolant through systems, then leave open.
12. Check battery condition, power down load, leave charges on.
13. Oil heaters – place five safety, thermostat-controlled AC heaters around the vessel at low points, open bilges and allow air flow to move around the vessel.
14. Protect and cover interior, use paint drop cloths for floors and furniture.
15. Bag linens and bedding – vacuum bag is a good way to do this.
16. Cover vessel – create a tent or shed around the whole vessel to keep weather and elements from damaging the decks and paint work. This will also help the ambient temperature inside the vessel.

A 20-foot container was placed under the vessel for all the deck gear, lines, fenders, etc., plus all of the paint supplies. It’s important to find all soda cans or any bottled liquids that could freeze and explode. All of this must come off the vessel.

The idea is not to let the vessel freeze in the first place, so run safety oil heaters 24/7 and have an LED lighting system running so the shipyard can see that power is on in the vessel. That way, they can reset it if it goes out. Have someone monitor the vessel daily to avoid the vessel going into a deep freeze. Adding coolant and antifreeze everywhere is purely a precaution.

De-winterizing vessel in spring thaw

Plan ahead for when the owner expects to use the yacht and prepare to de-winterize. We worked with the yard to capture and properly dispose of used antifreeze.

Once the vessel is unwrapped, cleaned and splashed back into the water, it’s a matter of running all systems by filling the fresh water tank with half a cup of bleach to every 500 gallons of water. This sterilizes the fresh water system. Then flush every point – for example, cycle the washing machine and any portable unit like ice machines with this bleach solution in the water tank. I would spend half a day running all points, then completely drain the freshwater tank and start a new tank with no bleach added. Then work on flushing the bleach from the lines.

There will be all the other maintenance to be restarted again, too. Whatever fuel was in the boat needs to be polished through a filtering system to start with clean tanks and fuel. This may be a good time to replace pump seals and impellers.

Capt. Rupert “Stretch” Lean started his career on large sailboats in 1981, then became captain in 1991. He enjoys working on motor yachts in the 100-foot range. Comments on this article are welcome below.