Not necessarily. If its (for example, an EC135) sat on a yacht then its generally non commercial operations so higher taxes. Fuel taxes as you are aware vary by country and it depends upon where the vessel was bunkered as to the VAT and MOT eligible.
Good point. However even taking all that into account I think 22,000 euro is a bit on the expensive side for 8000 litres of A1 (2.75 euro/litre).