Looks as though this is the shipping industry's reply to the IT's
BYOD hype.
BYOT -
Bring Your Own Tug.
So every container ship stacks a few of those and wherever she calls at no need for expensive third party tug assistance of the local port.
Maybe like BYOD often has been the IT sysadmins´security nightmare BYOT will cause port authorities some port traffic safety headaches?