Legal Definitions - historic bay

A historic bay is a body of water that a coastal nation has consistently treated as its own internal waters, subject to its full sovereignty, for a long period of time. This claim is recognized under international law even if the bay's entrance is wider than the standard 24 nautical miles typically used to define internal waters.

For a bay to be considered "historic," the coastal state must demonstrate:

• A long-standing, open, and effective exercise of authority over the bay (e.g., enforcing laws, regulating activities).
• The acquiescence of other states, meaning other nations have generally accepted or not significantly challenged this claim over time.

This exception to the general rules acknowledges situations where historical practice and international acceptance have established a particular legal status for a body of water.

Examples:

• Hudson Bay, Canada:

  Hudson Bay is a vast inland sea in Canada, with an entrance much wider than the standard 24 nautical miles. Despite its size, Canada has historically asserted full sovereignty over Hudson Bay, treating it as internal waters. This means Canada has consistently regulated activities such as fishing, shipping, and resource exploration within the bay, and other nations have generally not challenged this extensive claim over many decades. This long-standing, effective exercise of authority and the general acceptance by the international community allow Hudson Bay to be considered a historic bay, granting Canada complete jurisdiction over it.

• A Fictional "Bay of Serenity":

  Imagine the nation of "Aethelgard" has a large coastal indentation called the "Bay of Serenity," which has an entrance 60 nautical miles wide. For over 150 years, Aethelgard has strictly controlled all maritime activities within this bay, including requiring permits for foreign vessels to enter, conducting naval exercises without prior notification to other states, and enforcing its environmental and customs laws throughout the entire bay. No other nation has ever formally protested these actions or challenged Aethelgard's jurisdiction. Even though the Bay of Serenity's entrance is far wider than the standard limit, Aethelgard's consistent and unchallenged exercise of sovereign authority over such a long period, coupled with the international community's acquiescence, would likely qualify it as a historic bay. This allows Aethelgard to treat the entire bay as its internal waters, just like a lake or river within its territory.