I’m not an engine man, preferring to sail and enjoy the vagaries of wind and sea to the precision of  metal parts and fuel consumption.

On the other hand, I know the relief of the engine starting first time and the expectation of being back on the mooring in time for tea.

I look on it as a useful friend which will get me out of trouble if I really need it.

I keep it clean,  can change the oil and oil filter, and know more or less what this part or that part does – but have no overall grasp of it. In fact, I consider it a bit of a challenge.

So, realising that it was time for a proper service, I got the engineer from the Yanmar dealer in and watched him work. (It’s a Yanmar GM10)

A pleasure to see a job done well.

As you would expect – he worked methodically, step-by-step through the process.

And I recognised most of what he was doing, even if some of the bits were not quite where I thought they were.

But when he unbolted the alternator and moved it out the way, I knew I had done the right thing.

What was behind there? Well, the anode of course.

OK . . . . . so I didn’t know there was an anode in the engine. Makes perfect sense. Of course there is. Different metals sitting together in a wet environment.

This is what it looked like.

All you need to know is that a new one is over twice the size of this and a rather elegant dome shape.

I guess it hadn’t been changed for a long time – certainly in the time I have owned the boat.

Anyway, I’ve learned the lesson – and won’t forget it.