Sarah Laverick - Through Ice & Fire: the adventures, science and people behind Australias famous icebreaker

aft

At, in, or toward the stern.

athwartships

At right angles to the ships keel.

Beaufort wind scale

The Beaufort wind scale relates wind speed to observed conditions at sea.

beset, besetment

(Of a ship) Trapped in ice.

bow

The front or forward part or end of a ship, boat, etc.

brash

Brash ice is an accumulation of floating ice made up of fragments not more than two metres across. It is the wreckage of other forms of ice. Brash is common between colliding floes or in regions where pressure ridges have collapsed.

cod-end

The closed end of a trawl net, where the fish are trapped.

complement

The full number of officers, crew and passengers on board a ship.

davit

A projecting piece of wood or iron (frequently one of a pair) on the side or stern of a vessel, fitted with a tackle, etc., for raising, lowering, or suspending a small boat, anchor, or other weight.

diesos

Expedition diesel mechanics, often in charge of station refuelling procedures.

draught

The depth of water a vessel needs to float it.

frazil

Fine spicules or plates of ice, suspended in water. Frazil ice formation represents the first stage of sea ice growth, and gives the water an oily appearance. In the open ocean the crystals may form, or be stirred to a depth of several metres by wave-induced turbulence.

gangway

A platform and ladder or stairway slung over the side of a ship.

grease ice

A later stage of freezing than frazil ice, when the crystals have coagulated to form a soupy layer on the surface. Grease ice reflects little light, giving the sea a matt appearance. Grease ice behaves in a viscous fluid-like manner, and does not form distinct ice floes.

haul-out

Behaviour associated with pinnipeds (seals) temporarily leaving the water. Hauling-out typically occurs between periods of foraging activity.

hove-to

(Also heaving-to). When the ship slows right down in very rough conditions, maintaining just enough speed to keep a comfortable heading (generally into, or near-into, the wind and swell).

ice blink

A reflection of light off sea ice that is just beyond viewing range.

Inmarsat C

Communication via satellite, often used for emergencies at sea.

keel

In traditional wooden ship construction, the keel is simply the long, central wooden beam of a ship from which the rest of the ship is built, by adding ribs, etc. But for modern (steel) ship construction the keel is simply the first module of the hull, and the ship develops from this single module.

launching ways

The sloping structures (ways) down which a ship slides at launch.

lead

An open channel through a field of ice.

mess

A place where service personnel, etc., eat together.

nilas ice

A thin elastic crust of ice, easily bending on waves and swell and under pressure, thrusting in a pattern of interlocking fingers (finger rafting). Has a matt surface and is up to ten centimetres in thickness. May be subdivided into dark nilas (< five centimetres thick) and light nilas (> five centimetres thick).

Niskin bottle

A plastic cylinder with stoppers at each end, used to take water samples at a desired depth without the danger of mixing with water from other depths.

polynya

An area of open water surrounded by sea ice, as can occur in pack ice; of ecological significance when it recurs at the same time and place each year.

port, portside

The left-hand side of a ship or aircraft facing forward (opposed to starboard); larboard.

sastruga

A ridge, as in snow or sand, fashioned by the wind into a wave formation. Plural sastrugi.

starboard