A few months ago I wrote about words and phrases that have originated from the sea - to 'turn a/the corner', to 'learn the ropes', and to be 'left high and dry'. Another idiom that comes from nautical origins which people may not expect is to 'show a leg', meaning to get a move on and hurry up.
Rather than its figurative meaning today, the act of showing a leg was in fact literal for seamen who were part of the Royal Navy and their wives . Sailors were not permitted any onshore leave in case they deserted. Therefore, the wives of the sailors would come aboard the vessels and be allowed to sleep with their husbands. When the mornings came, the men had to get up to work while the women were allowed to stay in bed, or hammocks, as they would have been.
A member of the crew would check the hammocks to make sure none of the men were staying in bed and not working. The women would show their legs over the side of the hammock to prove their sex and right to stay in bed. If a hairy or masculine leg was shown, the sailor would be turfed swiftly out of bed to work, hence the phrase to 'show a leg'.