abeam: at right-angles to the length of a vessel.
abseil: method of descending a rock face by sliding down a rope,
aid climbing: pulling on or standing in slings attached to pitons (q.v.), bolts or hand-inserted wedges or cams.
arête: a sharp rock or snow ridge.
belay: a method of safeguarding a climbing partner from falling by paying out or taking in the rope and anchoring oneself.
bergschrund: the gap or crevasse between the glacier proper and the upper snows of a face (q.v.).
bilge keel: baby keels or projections on the outside of the hull running parallel to the central keel, which enable the boat to sit upright in shallow water.
bivouac: to spend a night in the open on a mountain.
boom: metal or wooden pole extending horizontally from the mast along the bottom of the mainsail.
bouldering: climbing unroped on boulders or very small outcrops.
broach: when the wind blows the boat right over on one side, so much so that the rudder comes out of the water and the boat is uncontrollable.
chimney: a fissure in the rock or ice wide enough to climb up inside, close hauled: when a boat's sails are pulled in as tight as possible so that the wind strikes them at an acute angle.
col: pass or dip in a ridge, usually between two peaks.
cornice: an overhanging mass of snow projecting over the edge of a ridge, formed by prevailing winds.
couloir: an open gully.
crackline: a crack or series of interlinked cracks in the rock that form a natural line up a rock face(q.v.).
crampons: steel spiked frames which can be fitted to boots to give a grip on ice and firm snow slopes.
crevassse: a crack in a glacier surface, which can be both wide and very deep, made by the movement of the glacier over the irregular shapes in its bed, or by bends in its course.
cwm: a deep, rounded hollow at the head or side of a valley, formed by glacial action.
drogue: improvised contraption pulled along behind a boat to slow it down in heavy weather.
expansion bolt: a bolt driven into a hole drilled in the rock which expands through internal pressure to create a friction grip.
face: a steep aspect of a mountain between two ridges.
fixed ropes: on prolonged climbs up steep ground the lead climber, having run out the full length of rope, ties it to an appropriate anchor. Subsequently all climbers move independently up and down the fixed rope, clipped on to it, using it either as a safety line or, on very steep ground, for direct progress. The rope is left in place for the duration of the climb.
foredeck: area of deck in front of the mast.
free climbing: climbing rock using only natural holds and not pulling on any of the running belays (q.v.).
Friend: a camming device placed in a crack used as a running belay or belay (q.v.).
front pointing: climbing straight up steep snow or ice by means of kicking in the front points of crampons (q.v.) and supporting balance with an ice axe or, on steep ground, using the picks of an ice axe and ice hammer in either hand.
gendarme: a rock pinnacle obtruding from a ridge, often surrounded by snow.
genoa sail: large triangular sail in front of mast which is so big that it overlaps the mainsail to some extent and gives the boat greater speed.
GPS: Global Positioning System – an electronic device that picks up the signal from three or four satellites to give an exact position on the surface of the earth or in the air.
gunwale: (pronounced gunnel) strip of wood or plastic running all the way round the outside of the boat at deck level to protect it from damage by other boats.
gybe: when the mainsail boom crosses from one side of the boat to the other as the wind changes.
halyards: ropes used to raise or lower sails.
jib boom: wooden or metal pole extending out from the front end of a boat to the outer end of which is attached the forward end of the jib sail (q.v.).
jib sail: triangular sail set forward of the mast.
jumar clamps: devices which lock on a fixed rope (q.v.) to support a climber's weight when subject to downward force, but which can be slid up the rope as a method of climbing it.
junk rig: boat with a four-sided sail which is stiffened with horizontal battens and pulled up a single mast like that of a Chinese boat.
jury mast: any temporary mast employed as a replacement after dismasting.
la: pass.
laybacking: the method of climbing a corner by placing the feet on one wall of the corner and using the corner crack for the hands to create an opposing force. Hands and feet are moved alternately upwards.
lead: area of open water between ice floes.
luffing: bringing the boat up into the wind so that the sails flutter and the boat moves more slowly.
moraine: accumulation of stones and debris carried down by a glacier.
offwidth crack: a crack that is too wide for hand jamming but too narrow to insert one's body (when it becomes a chimney, q.v.). Climbing these can be very strenuous.
pack ice: large area of floating ice in the polar sea.
pitch: section of climbing between two stances or belay points (q.v.).
pitchpole: when a huge wave comes up behind causing the boat to turn a complete somersault.
piton: a metal peg hammered into a rock crack to support a belay (q.v.).
portage: carrying a boat round an unnavigable stretch or land obstacle to the next navigable reach of water.
pressure ridge: a wall thrown up by the pressure of ice floes grinding against each other.
prusiking: climbing a rope using slings made from two thinner lengths of rope attached to the rope by a prusik knot that tightens and holds the body weight. The knots are pushed up the rope alternately. Purpose-made mechanical devices are also available.
reach: point of sail when wind is at right angles to the sail.
reef: reducing the area of sail exposed to the wind in heavy weather by rolling or tying canvas up round the boom.
rotor: a descending whirlwind caused by air that has flowed over the crest of a mountain peak.
sea anchor: throwing out any old thing on the end of a line in such a way that it will hold the boat's nose into the waves in order to ride out a storm more easily.
self-steering: a wind vane device fitted to the rear of a boat which keeps it facing into the wind on a predetermined heading while the yachtsman works or sleeps.
sérac: pinnacle or tower of ice, which is invariably unstable and dangerous.
sheets: ropes for controlling the trim of the sails.
shroud plate: metal plate on the sides of a boat's hull to which are attached the stainless steel wires giving lateral support to the mast.
sirdar: head Sherpa on an expedition.
standing wave: stationary wave in a river, caused by an underwater obstruction such as a boulder.
stays: stainless steel wire supports for the mast running fore and aft, to the front and back of the boat.
staysail: small triangular sail attached to the front stay.
stopper wave: a stationary wave which is breaking.
storm jib: smallest sail a boat possesses used in front of the mast in very heavy weather to provide basic stability.
sump: a cave passage completely filled with water, leaving no air space, also called a syphon.
traverse: to move horizontally or diagonally across a rock or snow slope. Also the ascent or descent of a mountain by different routes.
yards: horizontal spars two-thirds of the way up the mast which support the rigging.