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"Portholes
Sometimes, novice seamen will ask, "how come holes on the starboard side are called portholes instead of starboard-holes?" Many old salts are ready with explanations, but actually the name "porthole" has nothing to do with its location. The word originated during the reign of Henry V of England [1485]. It seems the good king insisted on mounting cannon to large for his ships, and therefore the conventional methods of securing the weapons on the forecastle and aftcastle could not be used.
A French shipbuilder named James Baker was commissioned to solve the problem, and solve it he did by piercing the ship's sides so the cannon could be mounted inside the fore and aft castles.
The French word "porte", meaning door, was used to designate the revolutionary invention. "Porte" was anglicized to "port" and later corrupted to porthole. Eventually, it came to mean any opening in a ship's side whether for cannon or not."