From Ocean Basins to a Bay: Eleven Waters by Scale

The largest and deepest ocean, recorded at about 161,760,000 square kilometres. It covers more area than all of Earth's land combined, and its Mariana Trench is the deepest known point in any ocean, at a recorded maximum depth of 10,935 metres. Start here to set the upper end of the scale.

Earth's second-largest ocean, recorded at about 106,460,000 square kilometres with a maximum depth of 8,486 metres. A mid-ocean ridge runs nearly its full length and continues to widen the ocean by a few centimetres a year, so this stop shows an ocean still being built.

A sea of the Southern Ocean off Antarctica, named for the British sealer James Weddell. It covers about 2,800,000 square kilometres and reaches 5,148 metres deep, and its cold, dense surface water helps feed the global deep ocean circulation.

A tropical sea of the western Atlantic of about 2,754,000 square kilometres, bounded by the Greater and Lesser Antilles, Central America and South America. Its warm surface waters feed the currents that help power the Gulf Stream, a warm counterpart to the Weddell Sea.

An arm of the northern Pacific, recorded at about 1,533,000 square kilometres, running along Alaska's southern coast from the Alaska Peninsula to the Alexander Archipelago. Its cold, storm-prone waters support major salmon and halibut fisheries.

A shallow sea between northern Australia and the island of Timor, about 610,000 square kilometres, linking the Indian and Pacific Oceans through the Indonesian archipelago. The Sunda Trench gives it a depth of more than 3,300 metres, and its seabed holds oil and gas shared by Australia and Timor-Leste.

A large, shallow gulf on Australia's northern coast between the Cape York and Arnhem Land peninsulas. It covers about 300,000 square kilometres but is only 55 to 66 metres deep in general, with a maximum of 69 metres, a sharp contrast with the deep ocean stops before it.

An arm of the Mediterranean west of the Italian Peninsula, enclosed by Sardinia, Sicily and Corsica, covering about 275,000 square kilometres to a maximum depth of 3,785 metres. Volcanoes including Stromboli dot the sea, and it was central to Etruscan, Greek and Roman seafaring.

A gulf about 1,126 kilometres long separating the Baja California peninsula from the Mexican mainland, covering about 160,000 square kilometres with depths exceeding 3,000 metres. The Colorado River historically fed its northern end, and Jacques Cousteau called it the aquarium of the world.

An arm of the Mediterranean between southern Italy, Sicily, Albania and western Greece. Calypso Deep, at 5,109 metres, is the deepest point in the Mediterranean and lies in this sea, and its coasts have long been a centre of Greek and Italian maritime trade.

The trail ends with an estuary: a large, shallow body on the coast of Northern California where the Sacramento and San Joaquin rivers meet the Pacific through the Golden Gate. Its recorded maximum depth is 113 metres, and it is the largest estuary on the Pacific coast of the Americas.