You need to lock it, otherwise people can not only steal it, but install their own lock.
Based on exploit complaint where Siege Engine was somehow inside Knarr hitbox (IIRC has been fixed) Knarr can NOT be hand-bashed.
https://ringofbrodgar.com/wiki/Snekkja seems to be in better shape, much of the info has been neglected to be copied over to Knarr page.