Sea legs

to get/find one's sea legs

Jasper would find his sea-legs in a fortnight, and a twelvemonth's v'y'ge would make him a man.

[…] and hear poor Mr Tapley, in his wandering fancy, playing at skittles in the Dragon, making love-remonstrances to Mrs Lupin, getting his sea-legs on board the Screw, travelling with old Tom Pinch on English roads, and burning stumps of trees in Eden, all at once.

Our passengers hailed from fifteen states; only a few of them had ever been to sea before; manifestly it would not do to pit them against a full-blown tempest until they had got their sea-legs on.

Had a refreshing walk up and down the quarter-deck, though I have hardly found my sea-legs yet.

It was fortunate for the passengers that most of them had at this period of the voyage got their sea legs; otherwise walking on the slippery deck, that seemed to heave as the rolling of the vessel threw its slopes up or down, would have been impossible.

When the ship was pitching or rolling, work would be difficult; but even then, when the Colonists get their sea-legs, and are free from the qualmishness which overtakes landsmen when first getting afloat, I cannot see why they should not engage in some form of industrial work far more profitable than yawning and lounging about the deck, to say nothing of the fact that by so doing they would lighten the expense of their transit.

So, from the Jurassic Period to today, the problems that come with being secondarily aquatic seem to have had the same kinds of solutions. And what we've learned is that it's no easy task to get your sea legs. But once you do, it's smooth sailing.