In mid-September the Thailand Navy received four more locally built M21 patrol boats and was happy to have them. Fourteen have been received or are on order so far. These 21.4 meter (68 foot) boats displace 43 tons and have a crew of nine. Max speed is 55 kilometers an hour and max range is 600-700 kilometers (depending on speed and weather conditions) and supplies (including 1,200 liters/400 gallons of fresh water) to stay at sea and under power for up to 24 hours.
Electronics consist of navigation gear and radios most often carried by sea-going ships including receiver for standard maritime distress beacons and transponders (including satellite based ones), along with a radar, depth-finder and GPS and gyro navigation systems. There is a public address system and search lights for dealing with small coastal craft encountered at night. Most coastal traffic encountered are legitimate but many of those travelling at night, especially with no lights, are not. The M21s carry an inflatable rigid boat in the rear for boarding parties or going close to shore in remote areas. M21s have a draft of 104 cm (3.4 feet) so that they can handle the shallow waters very close to shore.
M21s are armed with a 20mm autocannon in the front and a 12.7mm machine-gun and 81mm mortar in the rear plus small arms for the crew. The M21s are essential for dealing with the increase in smuggling (mainly drugs and people) in coastal waters.
Thailand has joined a number of other East Asian nations in creating a local ship building capability that can also produce licensed designs for warships. This trend began in the 1990s and Thailand has been at it since then with several new classes of ships. In late 2016 a Thai builder delivered the first of four M58 type patrol boats. These were built at a shipyard outside Bangkok as part of a program to replace an aging fleet of patrol vessels built in the 1990s and earlier. The 520 ton M58 type ship cost about $30 million each and is also offered to export customers by the Thai builder. The M58s have a top speed of 41 kilometers an hour and can stay at sea for about seven days at a time. The crew of 53 operates the radars and other sensors 24/7 as well as a 76mm cannon, a 30mm autocannon and two 12.7mm machine-guns.
Thailand is also building larger warships. In January 2016 Thailand ordered a 2,500 ton River class OPV (Offshore Patrol Vessel) from a Thai shipyard. This will be delivered by 2019. Thailand already has one of these in service. It was built in a British shipyard and delivered in 2015. The first River class OPV performed so well that Thailand now plans to build as many as six. These ships cost about $80 million each. The River class OPVs are a British design built in Thailand under license and with some foreign technical assistance. This is seen as a way to improve Thailand’s shipbuilding capability. The Thais worked with British shipbuilder BAE to develop modified version of the original River class ships. Britain was the first user of these ships and four entered service between 2002 and 2006.