Umm... I'm hesitating about the form of the verb. Should it be "Sunk" or "Sank" in this case?
Quick google search revealed that sank would be the correct past tense form of the word. For example "Kisaragi sank on...". Sunk would be used in the case of "Kisaragi was sunk on..." Or "Kisaragi had been sunk..." Since it needs these other verbs to go with it. At least to be grammatically correct.
Side note: that hairpin in ep12... Totally pointless and a reminder that no one really remembered her except Mutsuki.