After arrival in Dover, I started troubleshooting the engine. It turns out the water separator filter was totally stuffed with algae from the tank. I’m inclined to blame the Belgian uniforms again – having had the red diesel pumped out there, I only took a 100 litres of expensive white diesel in, as I was planning to once again fill my tank with red diesel in the UK.
Sounds like a big ironic joke, only it turned out to be one with a nasty side effect: What little fuel there was had been sloshing around in the near-empty tank, and together with the full steam ahead motoring around the traffic separation scheme, I had sucked most of the dirt out of my tank and into my diesel filter. So I started my search around town for alternator belts (can never have enough of those) and “Baldwin” diesel filters; sadly neither was readily available in the chandlery or car parts shops.