Three routes
Northern Sea Route. From the Kara Gate or the northern tip of Novaya Zemlya east along the Siberian coast to the Bering Strait. Shallow in places. Straits between islands and mainland. The most developed of the three: ports, icebreaker fleet, escort system, traffic control.
Northwest Passage. Through the Canadian Arctic Archipelago from Baffin Bay to the Beaufort Sea. Several possible threads between islands; the deep-water route runs through Parry Channel, the shallower ones further south. Poorly charted in parts. Choked with old ice pushed down from the north even in summers when the Siberian side is open.
Transpolar Sea Route. Straight across the central basin, avoiding any coast. Not usable by ordinary ships today. The route that a seasonally ice-free Arctic would open first for the strongest hulls, and eventually for others.
| Route | Coast | Ice conditions | Legal position | Development |
|---|---|---|---|---|
| Northern Sea Route | Russian Arctic | First-year ice; opens earliest | Russia applies domestic rules, permits and escort | Ports, icebreakers, traffic administration |
| Northwest Passage | Canadian Arctic Archipelago | Multiyear ice intrudes; variable | Canada treats it as internal waters; others call it an international strait | Sparse; few ports, limited charting |
| Transpolar Sea Route | None; central basin | Multiyear and thick first-year ice | High seas beyond coastal zones | None; theoretical for now |
Windows and hulls
Late summer to early autumn. That is the season. Earlier and later each decade, but still a season, not a year. Winter passage along the Russian coast is possible for ice-class ships with escort; nowhere else.
Hulls are rated. The Polar Class system, agreed through the International Association of Classification Societies, grades ships by the ice they are built to handle: from year-round operation in all polar waters at the top to summer and autumn in thin first-year ice at the bottom. Older Baltic and Russian ice classes still appear in the rules. A ship's class sets where and when it may go, and whether it must have an icebreaker alongside.
Ice-class hulls cost more to build and more to run. Thicker plate, stronger frames, protected propellers and rudders, heated ballast and deck equipment. A ship built for the Arctic is a compromise everywhere else.
The Polar Code
The International Maritime Organization's International Code for Ships Operating in Polar Waters. Mandatory for ships covered by the main safety and pollution conventions. Requires a Polar Ship Certificate and a Polar Water Operational Manual. Sets rules for structure, stability, machinery, fire safety, life-saving, navigation, communications, crew training. Restricts discharges of oil, sewage and garbage. Related measures address heavy fuel oil in Arctic waters; the current detail is on the IMO's own pages, linked below.
Whose waters
The United Nations Convention on the Law of the Sea sets the frame. Territorial sea, exclusive economic zone, continental shelf, high seas beyond. One clause, Article 234, lets coastal states make stricter pollution rules in ice-covered waters within their zones. Russia and Canada lean on it. Others read it narrowly.
Russia requires permits for the Northern Sea Route, mandatory escort or pilotage in ice, fees, and advance notice. Canada requires reporting and regulates through its own Arctic shipping rules. The United States holds that both passages are international straits with transit rights. The disagreement is long-standing and formally unresolved; in practice, ships comply with the coastal state and the flag states reserve their position.
Seabed claims are separate. Russia, Canada and Denmark on behalf of Greenland have filed overlapping submissions for the central Arctic shelf, including the Lomonosov Ridge, through the Commission on the Limits of the Continental Shelf. The water column above stays open regardless.
Hazards
Ice, obviously. Also darkness for months. Cold that freezes spray onto superstructures and shifts a ship's stability. Sparse charts, some based on soundings a century old. No harbours of refuge for long stretches. Search and rescue measured in days, not hours. Satellite communication that thins at high latitude. Fog when warm air meets cold water. And the environmental cost of a spill in a sea that freezes: oil under ice cannot be skimmed, and the microbes that break oil down work slowly in the cold.
Black carbon from exhaust settles on snow and ice, darkens it, and adds a local warming on top of the global one. A reason Arctic shipping is watched more closely than tonnage alone would justify.
Who sails
Most traffic is destination shipping: in and out of the Arctic, not through it. Gas and oil from the Yamal peninsula and the Ob estuary. Ore and coal from Siberian and Norwegian mines. Fuel, food and building materials to communities that have no road. Fishing fleets in the Barents and Bering seas. Cruise ships in Svalbard, Greenland and the Canadian archipelago.
Through-transit between Asia and Europe is a small share. Distance is shorter but the season is short, schedules are unreliable, insurance is costly, and container lines live on predictability. The savings on the map do not yet show up in the accounts. That may change; it has not yet.
Watching
Code and related measures: International Maritime Organization, Polar Code. Traffic and environment: Arctic Council working group on the Protection of the Arctic Marine Environment.