The good yachtsman's glossary

ANCHORAGE Depth of a waterway (for example, this canal or that river has 1.4 m of anchorage).
ASCENDING/UPSTREAMING Boat navigating towards the river-source, that is say sailing against the current. On a canal, this means that the boat approaches locks in an ascending direction.
BOATHOOK Long wooden or metal pole with a hook at one end. Use it when drawing alongside or drawing away and in locks to facilitate manoeuvring and avoid collisions.
BOLLARD Metal or concrete cylinder, sealed into a bank or quay, for mooring purposes.
BOW Front of boat.
CLEAT Metal fitting on boat to which mooring ropes can be attached. In general, boats have two cleats at rear and one or two in the front.
DESCENDING/DOWNSTREAMING Boat navigating towards the river-mouth, that is, travelling with the current. On a canal, this means that the boat approaches locks in a descending direction.
DOWNSTREAM Lower part of the river, towards its mouth.
DRAUGHT Vertical distance between the lowest part of a boat (in general the keel) and the waterline.
FENDER Of oval or round form, inflated with compressed air, arranged in series around the boat’s hull in order to protect it from knocks. Generally numbering 6 to 10, solidly made, bursting only under violent collision, and should be left in place even if you find them unattractive.
HEADROOM Height between the water-level and the crown of a bridge or other construction. For a boat, the vertical distance between the water-level (water-line) and the highest point of the boat.
HELM/TILLER The helm is similar to a steering wheel, the tiller is like a long bar situated at the rear of the boat. Both serve to steer the boat.
LOCK CHAMBER Part of lock between upstream and downstream gates.
LOCK PASSAGE Passage of a boat through a lock ; the time required depends on the difference in water levels as well as the size of the lock. In general, you should expect it to take a quarter of an hour.
LOCK SILL Sort of step on upstream lock-gate side in a lock where great care must be taken (see chapter on manoeuvres with sketch).
LOCK-WALL Lateral wall of a lock, whether vertical or slightly inclined.
LOWEST WATER LEVEL Lowest level of waterway or canal.
NAVIGATION CHANNEL This is the navigable zone shown on waterway Maps which must be kept to in order to avoid all Danger such as rocks, sandbanks, underwater Posts, etc…
OVERHAULING The act of overtaking a boat following the same route as you.
PORT Left side of the boat when facing the front.
REACH The part of a waterway or canal between two locks.
STARBOARD Right-hand side of the boat when looking towards the front.
STERN Rear of boat.
TO GO ASTERN To put the boat into reverse in order to stop it
TOPSIDE(S) Part of volume of boat above the water-line (see head-room). The greater volume of your boat above water, the greater the wind resistance always bear this in mind when manoeuvring.
TOWPATHS Paths along the canal or river and used until the beginning of this century for barge-towing by horses and men.
UPPER REACH Highest point of canal where the water division is
WAIST RAIL Strip of rubber or wood around the hull for protective purposes. Almost all boats are equipped with a (often just one, sometimes two or three) augmented with fenders.