Operation Deep Freeze 2006, MV American Tern, Krasin 200601

Ice navigation is a specialist area of

navigation Navigation is a field of study that focuses on the process of monitoring and controlling the movement of a craft or vehicle from one place to another.Bowditch, 2003:799. The field of navigation includes four general categories: land navigation ...

involving the use of maritime skills to determine and monitor the position of

ships A ship is a large watercraft that travels the world's oceans and other sufficiently deep waterways, carrying cargo or passengers, or in support of specialized missions, such as defense, research, and fishing. Ships are generally distinguished ...

in cold waters, where ice is a hazard to the safety of navigation. The presence of

sea ice Sea ice arises as seawater freezes. Because ice is less dense than water, it floats on the ocean's surface (as does fresh water ice, which has an even lower density). Sea ice covers about 7% of the Earth's surface and about 12% of the world's o ...

requires a ship to exercise caution, for example by avoiding

icebergs An iceberg is a piece of freshwater ice more than 15 m long that has broken off a glacier or an ice shelf and is floating freely in open (salt) water. Smaller chunks of floating glacially-derived ice are called "growlers" or "bergy bits". Th ...

, slowly sailing through a

lead Lead is a chemical element with the symbol Pb (from the Latin ) and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable, and also has a relatively low melting point. When freshly cut, ...

, or by working with an

icebreaker An icebreaker is a special-purpose ship or boat designed to move and navigate through ice-covered waters, and provide safe waterways for other boats and ships. Although the term usually refers to ice-breaking ships, it may also refer to smaller ...

to follow a course through the ice to a destination. Additionally ships must also deal with the extreme cold of the climate in regions such as the

poles Poles,, ; singular masculine: ''Polak'', singular feminine: ''Polka'' or Polish people, are a West Slavic nation and ethnic group, who share a common history, culture, the Polish language and are identified with the country of Poland in ...

; this involves removal of ice accumulation from the ship, as well as protecting the crew from the elements while working on the deck. Ships and their crews operating in ice will follow established rules of

seamanship Seamanship is the art, knowledge and competence of operating a ship, boat or other craft on water. The'' Oxford Dictionary'' states that seamanship is "The skill, techniques, or practice of handling a ship or boat at sea." It involves topics ...

, as well as complying with national and international regulations such as the

Polar Code The International Code for Ships Operating in Polar Waters or Polar Code is an international regime adopted by the International Maritime Organization (IMO) in 2014. The Code sets out regulations for shipping in the polar regions, principally relati ...

Areas of ice navigation

Ice navigation occurs wherever a waterborne vessel transits through

. One of the more common regions for ice navigation is the

Baltic Sea The Baltic Sea is an arm of the Atlantic Ocean that is enclosed by Denmark, Estonia, Finland, Germany, Latvia, Lithuania, Poland, Russia, Sweden and the North and Central European Plain. The sea stretches from 53°N to 66°N latitude and from ...

, where vessels visiting the

Baltic States The Baltic states, et, Balti riigid or the Baltic countries is a geopolitical term, which currently is used to group three countries: Estonia, Latvia, and Lithuania. All three countries are members of NATO, the European Union, the Eurozone ...

will make their way through first year ice in the

winter Winter is the coldest season of the year in polar and temperate climates. It occurs after autumn and before spring. The tilt of Earth's axis causes seasons; winter occurs when a hemisphere is oriented away from the Sun. Different cultur ...

months, often with an

Icebreaker An icebreaker is a special-purpose ship or boat designed to move and navigate through ice-covered waters, and provide safe waterways for other boats and ships. Although the term usually refers to ice-breaking ships, it may also refer to smaller ...

, or with ice reports, charts and data provided by meteorological offices. Other areas include the

Arctic Ocean The Arctic Ocean is the smallest and shallowest of the world's five major oceans. It spans an area of approximately and is known as the coldest of all the oceans. The International Hydrographic Organization (IHO) recognizes it as an ocean, a ...

, where increasing numbers of ships are transiting the region in the summer months for cruising and to transport cargo, as a result of oil and gas extraction in areas such as Yamal. The problems of increased shipping in

polar Polar may refer to: Geography Polar may refer to: * Geographical pole, either of two fixed points on the surface of a rotating body or planet, at 90 degrees from the equator, based on the axis around which a body rotates *Polar climate, the cli ...

regions presents additional challenges, including maritime safety concerns in the event that ice navigation is not carried out carefully. Ships will also pass through ice when navigating in the

Antarctic The Antarctic ( or , American English also or ; commonly ) is a polar region around Earth's South Pole, opposite the Arctic region around the North Pole. The Antarctic comprises the continent of Antarctica, the Kerguelen Plateau and othe ...

, although most ships are either

research vessel A research vessel (RV or R/V) is a ship or boat designed, modified, or equipped to carry out research at sea. Research vessels carry out a number of roles. Some of these roles can be combined into a single vessel but others require a dedicate ...

s or

cruise ship Cruise ships are large passenger ships used mainly for vacationing. Unlike ocean liners, which are used for transport, cruise ships typically embark on round-trip voyages to various ports-of-call, where passengers may go on tours known as ...

s that have been especially ice strengthened. Other significant maritime regions where ships will navigate through Ice include the

Saint Lawrence Seaway The St. Lawrence Seaway (french: la Voie Maritime du Saint-Laurent) is a system of locks, canals, and channels in Canada and the United States that permits oceangoing vessels to travel from the Atlantic Ocean to the Great Lakes of North Ameri ...

, around

Greenland Greenland ( kl, Kalaallit Nunaat, ; da, Grønland, ) is an island country in North America that is part of the Kingdom of Denmark. It is located between the Arctic and Atlantic oceans, east of the Canadian Arctic Archipelago. Greenland ...

and the Canadian coast, the

North Atlantic The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe a ...

during iceberg season and through the

Northwest Passage The Northwest Passage (NWP) is the sea route between the Atlantic and Pacific oceans through the Arctic Ocean, along the northern coast of North America via waterways through the Canadian Arctic Archipelago. The eastern route along the ...

Icing of superstructure

The accumulation of ice on the

superstructure A superstructure is an upward extension of an existing structure above a baseline. This term is applied to various kinds of physical structures such as buildings, bridges, or ships. Aboard ships and large boats On water craft, the superstruct ...

is a dangerous phenomenon. When the temperature is below slight icing will occur at winds of 5 Bft, moderate icing at 7 Bft, and severe icing at 8 Bft. When sailing in fresh water, icing will occur from and below. The more common causes of ice formation on the superstructure are from spray by wave crests and ship-generated spray. Other possibilities are snow fall, sea fog, a drastic fall in ambient temperature and also freezing raindrops in contact with the cold steel. The heading of the vessel relative to the wind and seas will determine which parts of the superstructure will ice first. Icing can immobilise equipment such as anchors or cause a dangerous list if the windward side of the vessel ices more heavily.

Ice detection by radar

radar Radar is a detection system that uses radio waves to determine the distance (''ranging''), angle, and radial velocity of objects relative to the site. It can be used to detect aircraft, Marine radar, ships, spacecraft, guided missiles, motor v ...

can be useful in detecting ice, but the returning signal which bounces off ice (even icebergs) is very faint, much lower than from ships. Conventional marine radars are designed for target detection and avoidance. Enhanced marine radars provide a higher definition image of the ice that the vessel is transmitting and will result in a much clearer image. This image can be used to identify the quantity and sort of ice that has to be dealt with. In standard radar, sea clutter affects the ability to see in the near vicinity of the vessel. An X-band radar set to a short pulse can give improved results.

References

Bibliography

* ''The Ice Navigation Manual'' (2019).

Witherby Publishing Group Witherby Publishing Group, formerly known as Witherby Seamanship, is a technical publisher of maritime, nautical and navigation training, reference and regulatory materials. The company is the resulting merger of Witherby Books and Seamans ...

. . {{Seamanship Exploration of the Arctic Navigation