Proportionate to the crime I assume you mean?
In which case, if the charge of "destroying ships" is proven - and I'm going to stick my neck out here and say being filmed taking a knife to a ship and destroying it, seems fairly cut and dried - then the crime carries a tariff of up to life in prison.
I assume you wouldn't complain if he got, say 10 years, as that would be proportionate to the crime he committed?