In a military context, the littoral includes areas of water, close to coasts, from which shore-based weapons can be a threat to major vessels afloat, where submarines can hide silently on the bottom, and small craft can make speedy attacks from hiding places. Amphibious warfare is also likely in the littoral environment.
See littoral warfare for techniques used for combat in these areas, sometimes called "green water" to distinguish them from the "blue water" of the open ocean.
Scope of the littoral
Traditionally, nations considered waters 3 nmi from their coasts to be territorial waters under their authority. The United Nations Convention on the Law of the Sea, and many countries, assume a 12 nmi territorial limit.
Two other concepts may apply. There is an UN-recognized Exclusive Economic Zone (EEZ), 200 nmi from the coast, in which a nation may control fisheries or other marine resource exploitation, even when beyond their territorial limits. This can get quite complex in narrow bodies of water such as the Mediterranean Sea, so littoral nations in such areas frequently establish bilateral agreements for resource management and environmental control in their overlapping areas of control.
There is also a frequently recognized Air Defense Identification Zone (ADIZ), where the coastal nations may challenge and identify aircraft within 200 nmi of their coast. This is usually interpreted as a right to intercept and follow the aircraft, not to attack it unless it shows hostile intent.
The littoral does not have a rigorous physical definition based on physical characteristics. Nevertheless, relevant terms include
- spray zone, also called supralittoral zone, from the high water mark to areas regularly splashed with seawater,
- sublittoral zone from the high water mark to the continental shelf