Some traditional nautical terms you must have heard- know the story!

There are some traditional nautical terms at ship that used frequently.But do we all know the history or story behind such names? If the answer is no then its our chance to know the story behind such traditional terms.
LOG BOOK:
In the old days of sail,literally the only way of determining a ship’s speed was to cast a small log secured to a line from the bow of a ship.by passing out the marked length of the line and timing how long it took for the log to reach the stern,the ships speed could then be calculated. During each watch, the log had to be cast every hour, and the ships speed and compass course noted in a book so the captain could use this for navigation. It soon became customary and then required to note other observations.
STARBOARD SIDE
The origin of the term starboard comes from early boating practices.Before ships had rudders on their center lines,they were steered by use of a specialized steering oar,which was held by on oarsman located in the stern of the ship and due to the prevalence of right-handed sailors,on the right hand side of it.The word starboard comes from old English “steorbord”  ,literally meaning the side on which the ship is steered.
PORT SIDE
An early version of port is larboard, which itself derived from MIDDLE-ENGLISH ladebord.The origin of lade has not been determined but some would connect it  with the verb lade (load) ,referring to the side on which cargo was loaded. The term larboard ,when shouted in the wind,was presumably too easy to confuse with starboard and so the word port came to replace it.Port is derived from the practice of sailors mooring ships on the left side at ports in order to prevent the steering oar from being crushed.
MONKEY ISLAND
During the ancient time when ship used to have masts and sails,the monkey island was also supposed to be located about 3/4th way up the main must on few ships. There is no solid evidence or proof to back the origin of the term “monkey island”;however there are few theories that believed to be the reason behind the usage.As per most popular theory ,some people believe that as the monkey island was located at the top of the main mast of sailing ships,sailors had to scramble up the ships rigging to free or repair the sails and rigging or to keep a lookout for icebergs,reefs,or land. Because the sailor had to climb as the monkeys do, this topmost place was termed as monkey island.
CAPTAIN
Latin in origin. “caput” meaning “head or leader”. The commanding officer of a military unit.It now refers to the commanding officer of a ship,regardless of his actual rank.
BO’SUN
Variation of “boatswain”.Medival english in origin . “Boot”(boat)+”swain”(boy or servant). A petty officer on a merchant ship having charge of full maintenance and related work.BOATSWAIN (pronounced bo’sun derived from ‘boat’ and ‘swain’ a servant).
FORECASTLE
The appropriate pronunciation for this word is fo’ksul. The forecastle is the forward part of the main deck.It derives its name fro the days of viking galleys when wooden castles were built on the forward and after parts the main deck from which archers and other fighting men could shoot arrows and throw spears ,rocks,etc.