We thought it was time to check how the diesel tank looks inside and possibly change the fuel if it's needed.
The tank has no inspection hatch, so it had to be done through the fuel gauge opening. Once opened, I could clearly see that the tank needs to be cleaned and the fuel is full of water. There was growth flowing in the fuel too which could clog the filters. Unfortunately the fuel gauge opening is very small, so my hand won't fit in, I had to find some other way.
Then I picked up a flexible "grabber" which can be used to grab stuff from difficult to reach places and used it with tons of paper towels to clean the tank.
We changed both fuel filters and filled the tank with fresh fuel. While at it, we also replaced all fuel hoses (6 meters of 8mm Lloyds approved marine grade hose) from the tank to the engine as the old ones were showing signs of wear.