Cathodic protection for your canal boat


Sacrificial metals

Low Profile

For the sides and baseplate


Fitting or replacing your anodes consistently will give your hull the best chance of a healthy long life, which benefits both you, your boat and your pocket in the long run.

Anodes on both the sides and the base-plate will enable a maximum 4 to 5ft radius of protection to be achieved by each anode, prolonging the health of your hull.

The repurposing of anodes which are not down to a 30% level is a good idea and we will only charge for rewelding them to your hull if we need to remove. Supply your own anodes and we will fit.

Magnesium Anodes:

  • Low profile 2.7kg for sides and base
  • All anodes are welded
  • Bring your own we will fit for you
  • Repurposing anodes means only re-welding is required

Your boats anodes are assessed out of water and it is totally up to you what you do from that point.

Each anode should be replaced by the time it reaches 30% of it’s original size at the very latest.


Prices per anode inc VAT

  • £ 85.00 Low Profile (fitted)
  • £ 30.00 Cust supply (welding only)
  • Removal of tags FOC
Corroded anode
Anode covered in weed growth
Anodes old and new
“Big love to all at P&S Marine, the team are all v knowledgeable and helpful, did a great job of blacking my hull, 4 shiny new anodes, and gave me some good advice on repairs. Absolutely worth the journey to get there. Also there was a cat 10/10 (Aug 2023)”

Emma N

Why Anodes

Over the 20 years P&S Marine has been in business, the difference in the condition of hulls with anodes regularly fitted and those without, is enormously telling.

A typical canal boat will be made up of a number of different metals that need protecting. For example, mild steel, stainless steel, bronze and brass. By introducing a less noble metal to the hull to act as a sacrificial material, it ensures that the important metals are not affected by electrolysis which is caused by the movement of water against them.

Simply: the anodes will corrode before the hull, propeller etc.

It is a myth that you do not need to protect the baseplate!! It is just as important as the sides and we recommend anodes are fitted every 8 to 10ft with 2 at the bow and stern.

Anodes are fitted or replaced after hull blacking.

Just remember the anode is a small sacrifice compared to your hull!

Other Services


The largest lifting capacity on the UK inland waterways


Dry docking for you and your boat, and free WiFi

Engine Servicing

Smooth your sailing with consistent maintenance

Hull Blacking

Two coats of SML bitumen for the
hull of your vessel


Fabrication, welding and overplating for your boat

Grit Blasting

Hull preparation prior to painting the base and sides


The most frequently asked questions about anodes are answered here, but if you would like to ask an additional question please click below
Do I really need anodes?

Yes. Of course, it’s totally up to you but we highly recommend anodes for protecting the whole hull.

I've been told anodes are not needed on the baseplate. Is this true?

No. The baseplate is just as susceptible if not more to corrosion as the sides. Steelwork is much more expensive than anodes.

Why do you use magnesium anodes?
Magnesium is a metal less noble than the other metals on your boat, beneath the water. The anode will corrode before the more important parts of your boat. Canal boats are most commonly used in fresh water. Magnesium is the best metal to use in fresh water, being highly active oxidising quickly, and becoming the cathode and protecting your hull.
What if I sail in brackish water?

Your magnesium anodes will corrode much quicker if you are constantly in brackish or sea water due to the salt content. Brackish water is found in estuaries where the rivers meet the sea. It is unlikely that the majority of canal boats will spend a lot, if any time in these areas. If you know that this is not the case, please speak to us directly and we will see how we can help. Of course you can always source your own anodes and we can weld them for you.

How many will I need?

We always assess your need for anodes once you are out of the water. We need to see which are corroded beyond further use and which can be repurposed. We recommend an anode every 8 to 10ft along the baseplate and every 5 to 6ft along the sides.