An enclosed sea, such as the Baltic or the Adriatic, lies wholly within the continental shelf and is surrounded by a landmass except for a strait connecting it to an ocean or another enclosed or semienclosed sea. Because of their restricted communication with the open ocean, enclosed seas have small tidal ranges or are tideless.
In an enclosed or semienclosed sea, the distances separating various points on the opposing shores are fairly short.
This is especially the case in enclosed and semienclosed seas, such as the Persian (Arabian) Gulf.
Here, this model was tested on a semienclosed sea
using observational data for reproductive activity and environmental variables.
For a blue water navy, general sea control is hardly possible without establishing not only control on the open ocean but also direct or indirect control of several critical passages of vital importance to the world's maritime trade, or by obtaining control of a given enclosed or semienclosed sea theater.
This objective is especially critical for naval forces operating in an enclosed or semienclosed sea. It is intended to obtain a sufficient degree of security for traffic in coastal waters and road/railroad traffic on the coast.
The South China Sea is a semienclosed sea
at the intersection between East Asia and the Indian Ocean region.
In the white paper, the group defines South China Sea as the "entire semienclosed sea
bordered by China, the Philippines, Malaysia, Indonesia and Vietnam."
In a typical enclosed or semienclosed sea, such an operational objective could be accomplished by massive strikes by surface combatants, submarines, and land-based aircraft.
A more likely scenario is a conflict between the navies of riparian states in an enclosed or semienclosed sea, or between a blue-water navy and a coastal navy operating in the littorals.
Today, a large-scale amphibious landing in an enclosed or semienclosed sea would be difficult to execute if the defender effectively used land-based aircraft, submarines, and combat craft in combination.
Carpio said China violated Article 123 of the Unclos regarding cooperation on enclosed and semienclosed seas