Why a Plymouth Pilot Might Be the Wrong Boat for You
“Do I really need to winterise my boat, or will she be fine?”
Now that we have hit October, it is a question I have already been asked, and I expect to be asked a few more times yet. It is a fair question. A large amount of the advice I have seen is generic, and focused more towards outboard motors or larger craft, with very little of it geared towards small inboard diesels that tend to spend their winter on, or near, the water.
What generally goes wrong over a winter is far less dramatic than owners think, and far more predictable in nature. When spring comes around, it often brings an all too familiar theme: the dreaded diesel bug, a flat battery and possibly a split pipe caused by a hard frost. Almost all of them can be traced back to a simple oversight, or something a new owner was unaware of, when the boat was laid up.
Do You Need to Winterise at All?
If the boat stays afloat and the engine is run regularly through the winter, it does not need winterising in the full sense. That side of things is covered in Can You Use a Small Boat All Year Round?. It still needs watching, and that is covered further down.
If the boat is coming out and will sit for months, then yes. The cold will not do the damage in a single night. The problem is that a diesel engine, a fuel tank and a battery all deteriorate when they are left to sit, and the work is far easier in October than in spring. If you are still deciding where to keep the boat over winter, How Easy Is It to Moor, Launch and Store a Plymouth Pilot? sets out the options.
Laying up is less about what you pour in and more about the state you leave the boat in, and having a thoughtful lay-up process or list.
Lay-Up and Commissioning Are Two Halves of One Job
The way I work, lay-up in the autumn and commissioning in the spring are separate jobs, and each has its own list.
At lay-up the engine is serviced, the raw-water side is filled with antifreeze, the tank is topped up and the batteries are dealt with. In spring comes commissioning: levels checked, a new impeller fitted, the engine run until it reaches its proper temperature and the battery checked to make sure it is charging.
Splitting the work this way means nothing dirty sits in the engine over winter, and nothing tired stays on the boat when it heads back in the water in spring.
Service the Engine as the Boat Comes Out
Most owners book the engine service for spring, so it feels fresh for the season. I prefer to do it as the boat comes out of the water. Used oil carries acids and contaminants from a season of running, and leaving them sitting inside the engine all winter is the opposite of what you want.
If you are not doing the service yourself, there is a second benefit. Spring is when every marine engineer is at their busiest, because everyone wants to be back in the water in the same few weeks and many owners like to be in by Easter. Book the service at lift-out and you are not fighting for your engineer’s attention at the busiest time of their year. Almost all the delays I hear about are from owners who have left it to the last minute to arrange their service and relaunch, and potentially miss their preferred relaunch date as a result.
What the service involves is set out in What Does Plymouth Pilot Maintenance Actually Look Like?. One thing a routine lay-up does not usually need is a coolant change. Depending on the type, coolant is changed every two to five years, so it is worth checking what is in there and when it was last done.
The Impeller: Check It, Leave It, Replace It in Spring
The raw-water pump has a small rubber impeller with flexible vanes, and it does the work of pulling seawater through the engine. Left in one position for months, those vanes take a set and lose some of their flexibility.
So at lay-up I take the old impeller out, check it is intact with every vane present and leave it in for the winter. The new one stays in its packet until spring commissioning. That way the impeller doing the work all season is one that has not spent the winter squashed in a pump housing.
Simple checks really do matter. A vane that has broken off does not disappear. It travels downstream, usually into the heat exchanger, where it can partly block the flow. The first sign is often an engine running hotter than it should, and finding a missing vane in October is far better than finding out about it on the water.
Antifreeze Where the Seawater Was
How an engine is cooled decides where the antifreeze goes.
Almost all modern engines are cooled through a heat exchanger. Seawater is pumped through one side of it, and a closed circuit of coolant runs through the engine on the other side. The coolant is already antifreeze and stays where it is. The part that needs attention is the raw-water side: the pump, the heat exchanger, the pipework and the exhaust.
Older engines were often cooled directly. Seawater runs straight through the engine block itself, with no closed circuit at all. We have one in the workshop at the moment, a 1973 Pilot 18’ still with its original Yanmar YSE8. On a directly cooled engine the antifreeze run matters even more, because whatever seawater is left behind is sitting inside the block.
Either way, the aim is the same: replace the seawater with something that will not freeze. There are two ways to do it.
The first is to close the seacock, take the lid off the strainer and pour antifreeze into it with the engine running, so the pump draws it straight through. Keep it topped up so the pump never runs dry.
The second is a spare length of hose long enough to reach a bucket. Fit it to the intake of the raw-water pump and let the engine suck the antifreeze up out of the bucket.
I have used both with great success. Access is often what decides it, more than anything else. Some engine installations make the strainer easy to reach, and others make the hose the simpler job. With either method, keep going until antifreeze shows at the exhaust. At that point the raw-water side holds antifreeze from end to end.
If there is a sink or freshwater tank plumbed in, drain it. A split pipe is a small repair, but an irritating discovery just before you start the season.
Fill the Tank and Think About Diesel Bug
Of all the stories I hear in spring, diesel bug comes up most.
Diesel bug is microbial growth that lives where water meets fuel at the bottom of a tank. The water gets in as condensation, which forms inside the tank as the air in it warms and cools. A half-empty tank holds more air, which means more condensation and more water for the bug to live on.
So the tank goes into winter topped up. A fuel stabiliser is worth considering as well, particularly if the boat is going to sit for a long spell or the fuel in the tank is not fresh.
The trouble with diesel bug is that it rarely shows itself ashore. It turns up on the first trip out, when a bit of motion stirs the sludge off the bottom of the tank and it reaches the filter all at once. You cast off and the engine runs perfectly as you motor away from your mooring, only for it to stop as you head out of the harbour, usually in the sort of sea state you least want to lose power in.
Fuel tanks on small boats like these generally have no drain, so there is no easy way to draw water off the bottom of the tank. The place to look is the water separator, which does have a drain. Water or a dark, slimy layer in the bowl is the early warning, and the separator drain is how you get it out.
Once the bug is properly established, it is a pain of a job. The tank has to come out to be cleaned, and every filter in the fuel system has to be changed. I have had to do it, and whilst the fuel tanks are removable, it can be a real nuisance when a full tank at the end of the season could have avoided it.
Batteries: Take Them Home or Keep Them Charged
Most small boats of this type run on lead acid batteries. A lead acid battery slowly loses charge even when nothing is connected to it, and one that is left sitting flat for long enough may not come back at all.
The simplest answer is to take the battery home and keep it charged over winter. If it stays aboard, it needs a trickle charge or someone checking on it regularly. A small 10-watt solar panel is enough to keep a single battery topped up. I fitted a semi-flexible one, and it did the job well. A mains charger works just as well where there is power.
There is one good reason to leave the battery in. If water getting into the boat is a worry, the automatic bilge pump, if one is fitted, needs a battery to run. Take the battery home and the manual pump is all that is left. This is perfectly fine under a good cover, but on a mooring it can be a different matter.
Where the Water Goes
Plymouth Pilots are not self-draining. Rain that falls into the cockpit runs into the bilge and has to be pumped out. That is a deliberate choice, because it lets the cockpit sit lower and deeper, which brings the weight down and keeps people well inside the boat. It also means that over winter the cover is doing real work.
Ashore, if a drain is fitted, make sure it is open. If not, the cover is all that keeps the rain out of the bilge, and the boat needs checking regularly.
A cockpit cover is generally enough. An all-over cover works well too. Whichever you use, protect any hard edges the cover sits on, because a winter of wind working the fabric against a corner will wear through the cover and mark the gelcoat underneath.
The cover should also be set up so that water runs off it rather than collecting. A sag that holds a puddle will eventually find its way in. Water trapped between the cover and the hull sits there for months, and on a boat with timber rubbing strakes or trim, that means the timber is kept wet all winter.
Staying Afloat: Check Everything, and Check It Before the Weather
For owners who leave the boat afloat, it needs regular checks, and the important ones come before a forecast of strong wind or heavy rain, not after it. Over a long wet week, the automatic pump can end up running on a battery nobody has charged.
A winter check is more than a glance from the shore: the cover and its fastenings, the water level in the bilge, the pump, the battery, the mooring lines and any chafe where they lead over the bow.
A boat that sinks afloat usually fills slowly over time, unobserved. One of my early jobs in the marine industry was helping out at a local marina, and part of it was going round the pontoons during and after bad weather, pumping out boats that had taken on water. In almost every case it was the same two things: a bilge pump that had failed or a cover that had given way.
The Seacocks
A Pilot 16’ or 18’ typically has one seacock, for the engine’s raw-water intake. A Pilot 24’ with a toilet fitted can have two more, for the toilet’s inlet and outlet. A single seacock is easy to look after, and just as easy to forget.
Lay-up is the best chance all year to work them. Open and close each one through its full travel. A seacock that has sat in one position all season can stiffen or seize, and the time to find that out is with the boat on the hard and a spanner to hand, not when a hose has let go and you need it shut.
Stern Gear and the Anode
With the boat out of the water, take hold of the propeller shaft just forward of the propeller and try to move it from side to side. A little play is normal. Noticeable movement means the cutless bearing is wearing, and that is a job far easier planned over winter than discovered in May.
Check the anode at the same time. If it is well eaten away, order the replacement now and fit it in spring. A new anode fitted in October spends the winter doing very little, while one fitted just before launch starts the season with its full life ahead of it.
A Winter Ashore Does the Hull Good
A fibreglass hull that has spent a season afloat takes up a little moisture through the gelcoat below the waterline. A few months ashore gives it the chance to dry out. Older boats kept afloat year after year, with no chance to dry out, are the ones where osmosis tends to show up, which is covered in What Is the Lifespan of a Fibreglass Boat?.
Start the List Before the Season Ends
The jobs list does not have to start at lift-out. It can start at any point during the season. As you notice things whilst out and about, make a note.
Once the boat is out, clean and dry, add to the list with a proper walk round. With the hull out of the water you can see things that have been hidden all season: the propeller, the keel bands and the underside of the keel where it has taken the ground.
If someone else is laying the boat up or storing it, hand the list over. It gives them a head start, and the jobs you have noticed get done over winter rather than discovered in spring.
Before we lay a boat up, we run through a series of checks of our own to pick up anything worth doing before spring. That list goes to the owner, and the owner decides what they want done. A winter is long enough to get through most lists, but only if the list exists in October.
What You Can Do Yourself
Yes, most of it. The oil and filter change, the antifreeze run, the impeller check, topping up the tank, taking the battery home, working the seacocks, fitting the cover and checking the cutless bearing and anode are all within reach of most owners.
Where a job needs specialist equipment or knowledge, it is best left to a professional. A diesel bug clean-out, with the tank coming out, is a good example. The lay-up itself is rarely the hard part. The hard part is the planning, so that it is all done before the weather turns.
What We Find in Spring
When a boat comes to us in spring without a service at lift-out, we find all manner of problems the owner had forgotten about over the winter months: failed impellers, blocked heat exchangers and flexible engine mounts that have collapsed.
When the service has been done at the end of the season, we do not tend to find surprises. The work was completed with plenty of time to spare, and spring is only a case of running through our normal checks to make sure she is shipshape and Bristol fashion.
Lay-Up and Spring Commissioning Checklists
Everything above is set out as a one-page lay-up checklist, in the order I work through it on the hard, with space at the bottom for your own jobs list. There is a matching spring commissioning checklist for the other half of the job. Both are worth printing and keeping with the boat’s paperwork, so next October starts from where this one left off.
[Download the lay-up checklist]
[Download the spring commissioning checklist]
What Spring Tells You
Laying up is not really about the cold. It is about leaving the boat in a state you would be happy to find it in: a full tank, a charged battery, antifreeze where the seawater was, only the new impeller to install and a list in the drawer.
Most of the spring stories I hear started with one of those being missed in October.