20 litres of Diesel in Water Tank

I would be very sceptical that it is even possible to eradicate the odour of diesel. Replace tank and all plumbing I would think which in some boats is a biig job.
The error was a catastrophic failure of a marina employee to employ due diligence, it is the marina's responsibility to replace the tank and the entire plumbing system imo. If it were me I'd be charging them for hire of a replcacement boat until the damage was repaired too. They have liability insurance.
 
I would be very sceptical that it is even possible to eradicate the odour of diesel. Replace tank and all plumbing I would think which in some boats is a biig job.
There's a fundamental assumption that the tank can be replaced. On my boat, the tank is an integral part of the boat, and hence not replaceable. On many others, it would require such major deconstruction as to be uneconomic. If the taint was truly not removable, the only possibility would be a liner of some description, and on some setups (inaccessible tank with internal baffles) even that would be impossible.

Steam cleaning is used to clean tanks etc. for use with potable liquids, so I guess that's the gold standard technique.
 
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