And he's writing a web diary for CBBC Newsround.
He tells us how he's keeping fit doing... aerobics
Diary entry 16:
I've been on this ship too long. I can find my way around far too well!
Today I got down to the hanger for aerobics.
I know, I know. But I don't get too much exercise on board.
Jumping on board
They have a number of exercise sessions a day. One's called The Pain Cage.
Not for me.
So I did Huffers and Puffers! Forty-five minutes of aerobics to dance tunes belted out in the ship's huge hanger.
Down one end a helicopter is being repaired - and in the middle, 12 of us dancing away!
The thing about being on a ship is it's difficult to keep fit. So each day most of the crew do at least one exercise session.
Which is why I've got into it all of a sudden.
Also it helps to get rid of the boredom. It takes your mind off the fact that nothing really changes on board.
And it wears you out so that you can fall asleep, despite the snores from the other people in the cabin... yes, they're still snoring!