Patrick O'Brian is a master of naval jargon, and such mastery can at times be overwhelming. This glossary is by no means exhaustive (hence "introduction") but should help you gain your sea-legs for your voyage!
To the front of the vessel.
To the rear of the vessel.
High in the masts or rigging.
In the middle of the vessel.
Shallow water in entrance to harbour.
Width of ship.
Change direction to sail before the wind.
Bottom compartment of ship, usually filled with waste water.
Nets strung out from ship’s side to stop boarding.
Ropes attached to sails to pull them forward.
Spar at the front of a ship.
Sharp turning of a ship.
Rope used to hold direction of a sail.
Slowing a ship so that it almost stops by heading it into the wind.
Internal partitions of ships.
Large cylindrical device that sailors inserted poles into to help haul up cables.
Lying a ship on its side to allow its hull to be cleaned.
System of using unpicked rope and pitch to seal gaps in planks.
Rigging a ship to sail directly into the wind.
single-masted small ship.
A warship without some, or all, of its cannons.
Front of a ship.
Small deck at front of ship.
Yard supporting top of a sail.
Platted rope holding sails to yards.
Ropes to raise or lower sails.
Stopping a ship by heading it into the wind.
Triangular sail at prow of ship.
A triangular sail.
Same direction as the wind.
A knotted rope and piece of wood that measures a ship’s speed.
Turn a ship closer to wind.
A four-sided sail.
Position a ship is in after being brought to.
Vertical spar from which sails and spars are attached.
Junior-ranking officers who would assist in the control of the crew.
Rear of a ship.
Sailor with limited experience.
The lowest deck on a vessel.
Small, fast ship for sending dispatches and orders.
Included gunner’s mates, quartermasters, master-at-arms, carpenter, bosun and cooper, the ship’s master, chaplain and surgeon
A ship’s boat.
Turn to windward.
Ropes attached to a ship’s shrouds that are used as ladders.
Lessen sail area by tying parts of it to the mast.
Square sails sitting beneath the topgallants.
Ropes attached to bottom corners of sails.
Support ropes attached to the masts.
A ship rigged with square sails at its bow.
Forwards and backwards support ropes for the masts.
Way of a ship zig-zagging into the wind or turning it by steering to windward.
Platform around the mast.
Highest of the three spars used to make a mast.
Turn a ship by moving prow in direction of the wind.
How far a ship is blown off course by the wind.
Horizontal spar that holds up the sails.
Outer sections of the yard.
Courtesy of The Napoleonic Guide.