Down to the yard to help out at a work party, but there were so many volunteers, I needn’t have bothered. So I had a brief poke about at the impeller before retreating back up town. Oh dear - I did some more googling of boatie blogs...

I've got a Vetus M2.D5 ................................................the issue I have with this engine is that it is set up for a boat where you have side access to the engine: all the bits that you can play with (fuel filters, impeller pump, oil filter etc.) are on the starboard side of the engine. This is OK if you have side access to the engine. If you don't have side access, it's a real pain. One thing I really don't get is that the impeller pump faces the stern and it is very fiddly to replace the impeller.
SECONDED!
I bought my Leisure 23 some 5 years ago with an almost brand new M2.D5 shoe-horned into it. Changed the impeller as part of maintenance and even with the adjacent oil filter removed it is a pig of job to say the least! You would struggle even if you fitted one of those "Speed Seals”.

One of the guys at the yard suggested I may have to lift the engine out. This is enough to upset my sleep patterns.

Anyway, I moved on! And bought a Christmas tree which, in a display of mild masculinity, I carried back on my shoulder. Move aside, laydeees of Comely Bank! Then it was out up town to the Filmhouse to see Carol. What a fabulous, sumptuously shot piece of work. And Cate Blanchett gets better and better, does she not. What presence. Jeesus. I better start my films of the year list soon. It’s certainly way up there.