Owners of yachts larger than 3.64 metres but without an engine will be paying an annual licence fee of €90.
Owners of tuna penning cages, maybe a bit larger than 3.64 metres, do not pay any fees.
The former, being wind-driven, do not pollute the sea and should be encouraged. The latter are definitely the worst polluters - ask any foreigner who dared to have a swim in the once clear waters along the whole coast from Marsascala to Wied iż-Żurrieq. The fact that tuna penning is an industry does not exonerate owners from being taxed to make good for pollution.