River-class Offshore Patrol Vessel

The River-class is a class of offshore patrol vessels built primarily for the Royal Navy of the United Kingdom. total of ten are planned for the Royal Navy; four Batch 1 and six Batch 2. The Batch 1 ships of the class replaced the seven ships of the Island-class and the two Castle-class patrol vessels. HTMS Krabi is a variation of the River-class design built in Thailand for the Royal Thai Navy. The ten ships of the Port of Spain/Amazona-class in service with both the Brazilian Navy and Trinidad and Tobago Coast Guard are also a variation of the River-class design.

Batch I

 * HMS Tyne (P284)
 * HMS Severn (P285)
 * HMS Mersey (P286)

Modified Batch I

 * HMS Clyde (P287)

Batch II

 * HMS Forth (P290) - fitting out
 * HMS Medway (P291) - under construction
 * HMS Trent (P292) - under construction
 * HMS Tamer (P293) - under construction
 * HMS Spey (P294) - planned for construction
 * HMS Ashburne (P295) - planned for construction

Brazilian Navy (Amazonas-class)

 * NRB Amazonas (P120)
 * NRB Apa (P121)
 * NRB Araguari (P122)
 * NRB Amapari (P123)
 * NRB Aiuruoca (P124)
 * NRB Alcântara (P125)
 * NRB Amandaú (P126)

Royal Thai Navy

 * HTMS Krabi (PC-551)
 * HTMS Unnamed (PC-552) - planned for construction

Trinidad and Tobago Coast Guard (Port of Spain-class)

 * Port of Spain (CG50)
 * Scarborough (CG51)
 * San Fernando (CG52)