get (one's) sea legs

1. To become acclimated to being on a ship. I'm afraid I'll have to spill my guts overboard before I get my sea legs on that whale watching tour. I hate this constant swaying—I don't know if I'll ever get my sea legs! Captain, how long does it usually take passengers to get their sea legs?

2. By extension, to become acclimated to something new. Oh, you've only been at your new job for a week—you'll get your sea legs eventually. I know you're nervous, but all freshmen are—you'll get your sea legs at school, don't worry. Once he gets his sea legs as a manager, I think he'll be a real asset to this department.

sea legs, to get one's

To adjust to a new situation. A sailor is said to get his sea legs when he is able to walk steadily despite the rolling and pitching of the vessel. The term was transferred to other kinds of learning experience by 1895, when David Lloyd George used it in a letter: “I have got my sea legs in the House. They now listen to me with deference.”