Thanks for this fascinating list of terms/phrases. I’ve added most of them to post one. I will observe that according to an online source that Splice The Mainbrace originally did refer to an emergency repair onboard a sailing ship.England being an island nation, there are literally hundreds of expressions that have entered the language from the navy. Here are a few of the lesser known ones.
To cut someone down to size: The width of a hammock was determined by a stick cut to the width of the shoulders. If someone made the stick too wide they were ‘a cut above themself’ and hence their crew mates would ‘cut them down to size’.
Sling your hook: to be told to pack up your hammock and leave.
Show a leg: on leaving port the cry would go out ‘show a leg’ and everyone sleeping had to stick a leg out of bed. Someone was tasked to go round the officer’s quaters. If it was a woman’s leg they would haul them out and kick them off the ship. Nowadays used to mean the same as ‘look lively’ or wake up and get on with it.
To make a rod for your own back: a punishment where you had to make the scourge that would be used to punish you.
Not enough room to swing a cat: this is disputed but it’s likely from the slave ships where the slaves were packed in so tightly there wasn’t enough room to swing the ‘cat ‘o’ nine tails’ and keep order. Nowadays used just to mean a very small space.
Son of a gun: from the time of ‘The Blocade’ when prostitutes remained on ship. If one got pregnant they traditionally gave birth on a section screened off on the gun deck. As the father of the child was unknown the certificate would read ‘Son of the gundeck’ later shortened to ‘Son of a gun'.
Between the devil and the deep blue sea: a plank running round the ship which was wet and slippery and thus treacheous and known as ‘the devil’. So to get round the outside of the ship you to hang onto the railn and had the slippery deck on one side and the sea on the other. Meaning to be between a rock and a hard place.
Splice the mainbrace: sounds like it should be an order to do something technical but it’s not. It’s an order to issue the rum ration (known as grog and hence drinking too much made you groggy). Nowadays used to mean get the drinks out.
Spoil the ship for a happenyworth of tar is axiomatic and is similar to ‘skin a flea for a farthing and spoil a penny knife’.