In our everyday language, we often use sayings without really knowing how they originated. Sayings such as “to swing a cat” or “down the hatch” or “break the ice”. These three have something in common: They all began life as naval slang.
The first, “to swing a cat,” has a rather gruesome beginning: It refers to the cat-o’-nine-tails, a whip made up of nine knotted cords roughly 75 cm long that was designed by the British Royal Navy to inflict severe pain and lacerate the skin. It was used in flogging for anything from drunkenness to mutinous talk to stealing. It was known as a “cat,” and obviously they needed room to swing it, to get the full effect. Today it merely refers to the size of a room or space as being “too small to swing a cat”. Another nautical idiom with cat was “to cat the anchor”: The cat referred to here was a large wooden beam on either side of the bow of a sailing ship which was used to support the weight of the anchor as it was raised or lowered; since there was usually the head of a lion or large cat carved at the head of the beam, it was called a cathead.
“Down the hatch” is more straightforward: The hatch was the covering of the hatchway on a ship, an opening in the deck which allowed vertical access into the hold for loading cargo. It means the act of drinking in particular, the mouth being the “hatch”.
“To break the ice” means to remove the invisible social barriers between strangers to ease conversation and social contact. It comes from the specialized ships called “ice breakers,” which were designed to plough through icy waters, making the passage of other vessels possible. Without such a ship, arctic expeditions could find themselves frozen in, land-locked by shifting ice sheets.
For many more sayings relating to naval history, check out “Not Enough Room to Swing a Cat” – Naval Slang and its Everyday Usage” by Martin Robson.
Language is a fluid concept, constantly changing, adapting, creating, compensating and inventing itself. Euphemisms are a prime example of that fluctuation and adaptation; successive generations come to know only the euphemism which in turn ceases to be one by that very definition, and which means that new ones will be invented to skirt the issue once again. For instance, there are hundreds of words for smell or stink, yet only a handful of satisfactory synonyms for words like fragrance, simply because hiding the ugly requires far more creativity than hiding the lovely. For that reason alone, writers who fall back on expletives like the highly offensive F-word (a euphemism for, well, you know) are simply lazy in my book; they’re missing a great opportunity for creativity! Interestingly, that word’s meaning has never shifted over time – it’s been in the English language since before the fifteenth century, and even then it was only written in cipher because it was too offensive to record in ink. In my opinion it still is, and one should consider 
Stephanie Huesler 