[LT Guppy]

He can come with you on sea duty.

On sea duty, you'll be assigned to a ship, but (with a couple exceptions) you'll come home every night.
The exceptions being when the ship is underway (short exercises, certifications or training, generally 1-6 weeks), the nights you have duty (once every 3-10 days, depending on the ship, you have to stay on the ship for 24 hours), or you are deployed (longer missions overseas (3-10 months).