A marginal sea is a part of ocean partially enclosed by land such as islands, archipelagos, or peninsulas. Unlike mediterranean seas, marginal seas have ocean currents caused by ocean winds. Many marginal seas are enclosed by island arcs that were formed from the subduction of one oceanic plate beneath another.

Marginal seas of the Pacific Ocean:

• The Bering Sea (separated by the Aleutian Islands)
• The Sea of Japan (by the Japanese Archipelago)
• The Sea of Okhotsk (by the Kurile Islands)
• The South China Sea (by the Philippines)
• The East China Sea (by the Ryukyu Islands)
• The Yellow Sea (by the Korean Peninsula)
• The Philippine Sea (by the Ogasawara Islands, the Mariana Islands, and Palau)
• The Coral Sea (by the Solomon Islands and Vanuatu)
• The Tasman Sea (by New Zealand)

Marginal seas of the Atlantic Ocean:

• The North Sea (separated by Great Britain)
• The Irish Sea (by Ireland)
• The Norwegian Sea (by Iceland, the Faroe Islands and Shetland)
• The Scotia Sea (by the Falkland Islands, South Georgia, and the South Sandwich Islands)

Marginal seas of the Indian Ocean:

• The Andaman Sea (separated by the Andaman and Nicobar Islands)
• The Java Sea (separated by the Greater Sunda Islands)

Marginal seas of the Arctic Ocean:

• The Laptev Sea (separated by the Severnaya Zemlya and the New Siberian Islands)
• The Chukchi Sea (separated by Wrangel Island)

Note that although the Caribbean Sea is enclosed by most of the Antilles and the mainland of the Americas, it is not a marginal sea because (together with the Gulf of Mexico) it forms the American mediterranean sea and its currents are mainly caused by salinity and temperature differences rather than by ocean winds.