There are no such things as a Seaworthiness Certificate or classification rules for war ships. Merchant ships must provide at PSCs plenty certificates about safety, protection, pollution prevention, radio, load line, ISM, security, etc, but no seaworthiness certificate. Reason is that seaworthiness is the responsibility of the ship owner alone to ensure that the ship is seaworthy. It includes the duty of the ship owner to provide a capable crew to operate the ship, which doesn’t seem to be the case here. I am still mystified about the structural damages of HI. We have been told that the starboard anchor of Sola TS ripped open the aft starboard deck house above waterline, but ships do not float on deck houses. Divers must have inspected and taken pictures of the wreck’s underwater hull and the damages there. Anyway, the war ship is a CTL and cannot be repaired. Easiest is just to leave the wreck where it is. I agree with you that the Swedish Royal Navy is a joke today with some corvettes, a submarine and some ‘war” boats for military action. It wasn’t much better 1965/70 when I served.
I note that the Norwegian Armed Forces Materiel Safety Authority issues something called a Seaworthiness Certificate but I haven’t got a clue what that piece of paper is all about.