"Posh"
This term may originate from the early cruise lines that offered wealthy passengers cabins that were on the Port side going Out and on the Starboboard side coming Home to avoid the sun's heat and glare.
"Feeling blue"
When a ship's captain died during a voyage, his ship would return to port flying a blue flag and bearing a blue stripe on its hull. The term "feeling blue" signifies depression or sadness today.
"Three sheets to the wind"
This expression for drunkenness was born on the high seas. Sheet is the nautical term for a rope that controls the tension on a square sail. If the sheets were loose on a three-masted ship, the sails would flap in the wind. A ship with its sails in the wind would drift out of control until the situation was corrected. Thus, the modern phrase,"three sheets to the wind" has come to signify a person who is drunk and out of control.
"As the Crow Flies"
Crows were an essential part of the early sailors' navigation equipment. It was known that crows detest large expanses of water. So, these land-lubbing fowl were carried aboard to help the navigator determine where the closest land lay. In cases of poor visibility, a crow was released and the navigator plotted a course that corresponded with the bird's flight. The bird invariably headed straight "as the crow flies" toward land.
"Cold enough to freeze the balls off a brass monkey."
Every sailing ship had to have cannons for protection. Cannons of the times required round iron cannonballs. The master wanted to store the cannonballs such that they could be of instant use when needed, yet not roll around the gun deck. The solution was to stack them up in a square-based pyramid next to the cannon. The top level of the stack had one ball, the next level down had four, the next had nine, the next had sixteen, and so on. Four levels would provide a stack of 30 cannonballs. The only real problem was how to keep the bottom level from sliding out from under the weight of the higher levels. To do this, they devised a small brass plate ("brass monkey") with one rounded indentation for each cannonball in the bottom layer. Brass was used because the cannonballs wouldn't rust to the "brass monkey", but would rust to an iron one. When temperature falls, brass contracts in size faster than iron. As it got cold on the gun decks, the indentations in the brass monkey would get smaller than the iron cannonballs they were holding. If the temperature got cold enough, the bottom layer would pop out of the indentations spilling the entire pyramid over the deck. Thus it was, quite literally, "cold enough to freeze the balls off a brass monkey."