Yep it's true. After you've been out at sea for a few days your inner-ear adjusts to the constant motion it's subjected to, and you compensate for it as you walk. It's a strange feeling at first to be walking down a passageway, only to be walking UP the passageway a few seconds later as the ship rolls a bit.
You know you have your Sea Legs when you can walk down the stairs ("ladders" on a ship) from the mess hall with your left hand on a rail, a full cup of coffee in your right hand, and not spill a drop.
It took most of the morning, but now I can walk a straight line through the house without wandering as I do it!
AND...Sunday on way back in, somewhere in the vicinity of Guadalupe Island, we started hearing jets. I saw some F-18 Hornets around, and wondered what they'd be doing that far out. About an hour later I went up on deck, and was greeted by an Nimitz-class carrier, and an Arleigh Burke class guided-missile destroyer!
I'll post some pix after I get them downloaded from my camera.