In a class of their own: new corvettes take centre stage

Not too long ago, the task of categorising the ship type known as a corvette was largely one of deciding where a heavily armed fast attack craft (FAC) became a small corvette – generally around 500 tons displacement – and where a large corvette became a light frigate, usually around 2,000 tons.

According to this simple definition, every fast, well-equipped warship that falls into this size bracket must be a corvette if it is capable of littoral combat operations against surface targets and submarines and self-defence against aircraft.

However, political considerations have added another dimension to the classification dilemma, with some governments and navies preferring the expression 'offshore patrol vessel' (OPV) in the initial stages of a new ship's existence, before its true colours – and warfighting abilities – are revealed.

On the other hand, the diverse types of mission fulfilled by contemporary naval forces warrants a significant crossover between ship types and further dilution of the meaning of the term corvette.

These changes are related to the increasing importance of maritime security tasks that go beyond the patrol and defence of territorial waters out to 12 n miles. Since 1994, when the UN Convention on the Law of the Sea came into force, nations have found that exclusive economic zones (EEZs) of up to 200 n miles require surveillance.

Missions now encompass the protection of sea lines of communication and offshore facilities such as oil and gas platforms; law enforcement, counter-narcotics and anti-smuggling tasks; search-and-rescue (SAR); and disaster response.

Standing alongside the traditional tasks of strike operations in limited theatres of operation, these new roles mean there is a considerable demand for multirole capabilities and an expansion of reach and endurance.