That is what the Captain of a nuclear submarine says when he goes to his stateroom and leaves the First Officer in charge.
It’s a big deal for the First Officer.
He knows he can always get the Captain if he has to but he doesn’t want to because he wants to show that he too can be the Captain and one day will move on to being a Captain.
The trick for the Captain is to regularly utter the words “you have the conn”, pushing his first officer into situations of difficulty and stress, to allow him or her to deal with the difficulties and the stress.
That’s how leadership probably works, that’s how delegation probably works.