Sail or motor your boat round to MES Ltd. We are in a superb location.

Launch boat North Wales

We are sited in a new 3500 sqft modern workshop less than 4 meters away from one of the largest boat slipways in North Wales at Dinas boatyard Port Dinorwic, Y-Felinheli near to Port Dinorwic Marina on the Menai Straights.

Whether your boat is moored in North Wales or you are passing through if you need our services you are able to moor up alongside our workshop at Dinas boatyard for us to assess your boat for repair.

Boat owners berthed at Dinorwic Marina are only a couple of minutes away from us by sea so why not pop round and use our services. We have 6 staff so we can offer a fast response along with a huge wealth of experience and have been in Port Dinorwic now for 20 years.

Best part is we are very nice friendly people and normally have 5 or 6 types of coffee on the go – free for customers!

Drop in and see us or better still bring your boat with you!!

Boat launch North Wales


Tips for successful launching include:-

  1. Check boat trailer and tow vehicle are in working order. Life jackets and safety gear on board
  2. Check slipway for obstacles, water depth and slippery surfaces
  3. Check boat – engine starts, fuel level, bung is in, steering is in straight position, trim control working.
  4. Select 4 wheel drive if vehicle is so equipped
  5. Now check trailer – disconnect cable to power lamps to prevent damage, remove tie in straps, unhook straps to winch mechanism
  6. Helper should climb on board (who is familiar with the steering etc. of the boat).
  7. Reverse trailer down slipway – being in a position to communicate with your helper. Keep it straight. Keep speed in check when boat is entering water. Halt tow vehicle before its wheels enter the water. Your boat should be floating free and your helper should be checking the steering and reset trim prior to starting engine.
  8. Use minimal throttle to move the tow vehicle and trailer back up the ramp away from the boat. Park up in suitable location and secure.
  9. Launching without a helper is much more difficult, and less fun! The essential difference is that you need a mooring line so the boat doesn’t float away without you. The mooring line (rope) should be tied loosely to either a dock or to the trailer until you’re onboard. When you have got the vehicle and trailer down the slipway into position for the boat to be buoyant carefully climb aboard. Once onboard, detach the mooring line (rope), lower the trim, start the engine and motor the boat to a dock or to the shore. Then go back to your vehicle and trailer and move them to a suitable position before going back to the boat for a day of fun.


Boat winterisation North Wales

MES Ltd based in North Wales can provide you with a winterisation and inspection service. Should you require boat winterisation North Wales, please contact us by phone or email.

If you are planning to take your boat out of commission over the winter, then it is important that you winterise the engine and boat, otherwise come the spring, you may start to incur problems before you launch.

There are different levels of winterisation dependent on the boat/engine and should be done in line with the manufacturers recommendations. List of care for your boat during winter is provided below but this is not exhaustive and includes:-

1.    Fill your diesel fuel tank to the top – this helps prevent condensation from building up inside the tank thus minimising the chance of diesel bug growth. Fuel additive maybe required to be added if there are suspect signs of the bug.

2.    Check fuel filler cap seal – this is to stop any water from entering the fuel tank to eliminate risk of diesel fuel bug growth.

3.    Change the engine oil – run engine up to temperature, drain oil and refill with correct grade oil for your engine. This safeguards the engine from any corrosive acidic remnants of combustion remaining in there over the winter. Oil should be responsibly disposed.

4.    Change the oil filter – Combustion products can build up in the filter which restricts the flow so it is a good idea to change a minimum of once a year and in line with manufacturer’s recommendations. This can be a messy job and filters should be responsibly disposed.

5.    Change and drain fuel pre-filter – this can establish if there is a problem with the fuel

6.    Check fresh water cooling level and top up – check the condition of the anti-freeze (correct ratio of water to anti-freeze). Anti-freeze guards the engine from the cold and, also acts as a corrosion inhibiter protection the internal water ways within the engine

7.    Drain the cooling system for raw/fresh water cooled diesel engines, refill with anti-freeze solution and run up engine to circulate the solution around

8.    Check the sea water pump impeller – if impeller remains in one position for too long it can become deformed and less effective. Impellers should be changed annually as a minimum.

9.    Clean and inspect the engine. Look at the electrical wiring, check for water, fuel or oil leaks.

10. Clean bilges – this helps spotting any faults easier and earlier.

11. Disconnect batteries, check levels and charge up (check and charge every month to keep them in order). Batteries may need replacing if not keeping their charge.

12. Prevent rust build up by removing air intake filter and block entry with something like an oily rag.

13. Block off the exhaust (for example using tape, rags or bung) to help prevent moisture from getting into the engine

14. Don’t forget about the interior upholstery and furnishings which may need to be removed. Ventilate areas by leaving cupboard doors ajar etc.

We also have indoor secure storage facilities within our premises should you wish to place your boat undercover for the winter.

Boat winterisation North Wales

Fabrication and welding work

If you require any fabrication or welding work for your boat for example Brackets, Stanchions, Pushpits, Pulpits, Gaurdrails, Tanks, Pipework etc made from stainless steel or aluminium then please contact Marine Engineering Services ( M.E.S. ) Ltd of North Wales. Specialising in Boat Engine Service and Repairs for 20 years we now also employ a very experienced fabricator who can custom build the  above to suit your boat. So if you are in need of specialist bespoke fabrication or welding requirements then please do not hesitate to contact us on 01248 671215 or email [email protected] for further discussion.


Emergency boat engine repairs for boat owners in North Wales.

When a boat engine stops working whilst out at sea, it can be a very scary moment. It all goes suddenly very quiet, then panic can set in when you realise you are drifting and you don’t know what is wrong with the engine or how to help yourself.
However, with some basic knowledge and some pointers on your own engine, you will be in a better position to fix the fault out at sea on your own or enable you to get back to shore safely. This knowledge will give you peace of mind and hopefully keep you calm if such an incidence happens to you.

Here, at MES Ltd, we believe every boat owner should have tuition on fault finding, basic understanding and maintenance.
MES ltd can give you one to one tuition on your boat and will create this around your needs and current understanding. It will be relevant to the boat that you own. The basic lesson will take around an hour and cost £46.50 plus vat . We can build the lesson up from this should you require a deeper in depth knowledge base.

Pre season boat engine service North Wales

Pre season boat engine service North Wales

MES Ltd would recommend a pre season boat engine service prior to the boating season commencing. This should help ensure a trouble free boating season so that you can sit back and enjoy.
At MES Ltd, based in North Wales, we have been servicing marine boat engines for 20 years. We service a wide range of engines and we can attend your boat at its location or any of the local marinas such as Caernarfon, Conwy, Deganwy and Holyhead. You can also have the service carried out at our purpose built workshop in Port Dinorwic.

If you have a yacht, motor boat, speed boat or Rib it would be a good idea to have a service on the engine once a year. So if you did not have the boat serviced at the end of the last boating season then now is the time to carry out an engine service. Even if you did not use the boat much since the last service things unfortunately still deteriorate over time so having the oil and filters changed and a visual inspection of hoses and belts etc. will help ensure that you have a safe and enjoyable time out on the water. You can undertake these tasks yourself, or if you are not sure how to accomplish a boat engine service and visual inspection then we will be happy to help.

We are agents for most popular boat engines such as Mercury, Beta, Cummins etc. We have factory trained marine engineers using quality parts and tailor the service to meet your needs. We sell and stock many service parts, so please contact us if you require any assistance to enable you to service your boat in readiness for an enjoyable and relaxing boating season ahead.

boat service north wales

Please contact us for a service check list sheet.

Boat engine Heat Exchanger Service

Boat engine heat exchanger service

Following on from our blog on overlooked maintenance items on your boat engine, we will now delve deeper into the purpose of its heat exchanger.  During a service the boat engine heat exchanger service should also be considered. The heat exchanger on your boat is there to regulate the temperature of the fresh water and antifreeze mix (fresh coolant) which cools the boat engine.

Most marine engines have fresh coolant which is pumped around the engine to keep it running at its optimum temperature. When the engine reaches its optimum temperature, the fresh coolant also needs to be kept at this temperature.

The optimum engine running temperature is achieved by:-

the thermostat opening and closing, allowing the fresh coolant to pass through the engine.

the fresh coolant being passed through the heat exchanger.

The heat exchanger is basically a tank in which the fresh coolant passes through. There are copper tubes located within this tank which has the sea water (at seawater temperature) passing through them. The fresh coolant (with a temperature of around 800C) is pumped through the tank and comes into contact with the cooler copper tubes. These tubes are cooled by the seawater supplied by the engines raw water pump (seawater pump) so that the temperature of the fresh coolant is lowered enough to allow the thermostat to continue to regulate the temperature of the engine.

Without the heat exchanger, the temperature of the engine would continue to rise as it works which in turn would cause the fresh coolant temperature to rise to boiling point, resulting in the engine overheating and failing.

During the heat exchanger service, both the seawater and fresh water parts of it need to be striped and cleaned. This is done by removing the end caps on it and sliding out the bundle of copper tubes. The engines cooling systems need to be drained for this to be completed. After cleaning in a specialist bath and fluid, the heat exchanger should be re built with new seals and pressure tested for leaks. New fresh coolant (fresh water and fresh antifreeze mix) should be added at this time.

The antifreeze does two jobs:-

it stops coolant freezing in cold weather

it minimizes corrosion of the fresh cooling system and the cooling passages in the engine.

The engine should now be run and checked for leaks etc. Then that should be it- job done!

If your engine temperature starts to rise above normal when working hard it could well be that the heat exchanger needs a service. A visit from one of our trained engineers would confirm this and if you wish we could also carry out this work for you.

Bon voyageboat engine heat exchanger

Boat service North Wales, check list

Boat service North Wales, check list

The below blog is aimed to provide information to our customers regarding boat service North Wales, check list and other overlooked maintenance items. We hope that you will find it useful for your boating enjoyment.

This is the first, of our soon to be regular blogs, on boat engine and boat related maintenance items.

Overlooked engine maintenance items on annual boat service

If you service your own boat engine or have just purchased a used boat then the following are some items on the engine that will require periodic attention. If the below items are overlooked this can cause a mechanical breakdown.

Engine valve clearance adjustment which should be done on top of your annual boat service. Every 2-3 years

Unless you are a competent experienced engineer this is best left to the specialists. This is recommended because as the engine wears internally, the settings can go outside of the tolerances and thus require resetting. This will improve performance and smoothness of operation.

Engine Heat Exchanger and Intercooler removal and cleaning. Every 2-3 years

Specialist work as both can cause major problems if not re-assembled and pressure tested correctly. Please contact us for advice. The engine fresh coolant should be changed at the same time as completing this work. This work is essential to maintain the engine’s correct working temperatures for the cooling system and the air intake system if the engine is turbocharged.

Engine mounts and prop shaft alignment checks. Every 2-3 years

This can be checked by the average DIYer. If you are unsure then please contact us for further advice. Note that the prop shaft alignment needs to be within 4 thousandths of an inch. The stern gland will also need checking and adjusting with this job. This is recommended as the engine mounts deteriorate over time and would cause the engine to become misaligned creating excessive wear on the prop shaft bearings and other components.

Service check sheet

Along with the regular service (please contact us for a free service check sheet for you to work through) if the above items have been attended to, you should be in a good position to have a trouble free season on the water.

Until next time, enjoy

We do stock many boat servicing parts, so please contact us for further details and to help and advise you.

We would welcome feedback to this post and also suggestions for future items.

Boat service North Wales, check list

Rob, marine engineer for MES Ltd, is pictured here. He has removed the heat exchanger and intercooler from the side of the engine for servicing. The image is showing him actually adjusting the valve clearances.




ZD76  ANODE (NEW)  £25.00 plus VAT

Zinc bolt on anode up to 110mm bolt centres for use in salt water

Normal Weight:  1.35Kg

Manufacturer:  McDuff

Length:  N/a / 200mm

Depth:  33mm

Stud M10

One fixing hole 110mm  x 12mm

Slot hole 0mm-110mm centres