Counter-piracy techniques will be a highlight of Imdex 2011, the biennial maritime defense exposition in Singapore, May 18-20. The show and concurrent International Maritime Security Conference will feature the latest technologies and research developments in maritime warfare and counter-terrorism operations.

Despite recent successes at thwarting their attacks, pirates continue to exact a toll on merchant shipping using a range of tactics. Merchant vessels are normally ill- equipped to fight off pirates—their crews are small and untrained in the use of defensive weapons—and often unable to obtain assistance while under attack. (Two articles on antipracy measures begin on p. 37.) Navies employing conventional measures against piracy—and terrorism—face a challenging mission, beginning with the relatively small number of vessels that are available to patrol large areas of ocean.

Unable to escort every merchant vessel, navies are looking for ways of improving situational awareness, persistent surveillance, pre-attack detection and response to attacks, especially in the most notorious areas for piracy, such as the Bab el-Mandeb Strait in the Red Sea, waters off the coast of Somalia and the Strait of Malacca.

Situational awareness, early warning and rapid response have become critical elements of antipiracy missions, both to deter hostile actions and minimize the risk of attack. Unmanned aerial vehicles (UAV) are increasingly used for maritime surveillance. Medium-altitude, long-endurance (MALE) versions of UAVs perform extended-range maritime patrols, some lasting more than 24 hr., and carry the same sensors as manned platforms. These UAVs provide commanders with a situational picture far beyond the horizon, enabling them to task their units to suspected threats detected throughout an operational area.

MALE drones designed for maritime surveillance include the U.S. Navy's shore-based Broad Area Maritime Surveillance (BAMS) platform, developed by Northrop Grumman and based on that company's Global Hawk UAV, and the maritime surveillance version of Israel Aerospace Industries' (IAI) Heron. While BAMS will enter service in 2014, the Heron is operational with two squadrons of the Indian navy. The Heron UAV operates from shore, linking to naval units at sea upon arrival over the patrol area. The surface-search radar, electro-optical payloads and electronic surveillance systems, including electronic support measures and communications interception, transmit information via data links to the ship, where it is monitored by the combat information center and integrated with onboard sensors. Australia is interested in UAVs for similar missions and evaluated the Heron last year. Singapore has explored the option of using the smaller catapult-launched Boeing ScanEagle UAV aboard its vessels.

While MALE UAVs are suitable for the littorals and to distances of several hundreds kilometers at sea, blue-water navies require a different platform that can be deployed from the vessel itself.

IAI is working with Hindustan Aeronautics Ltd. of India on developing the Naval Rotary Wing UAV (NRUAV), a Cheetak naval helicopter modified into a UAV that carries a mission payload similar to that of a Heron. Guided by sensors, the NRUAV will take off and land on a vessel in conditions that would be difficult for piloted helicopters, and provide endurance exceeding that of manned aircraft. NRUAV can be considered an elevated mast.

While the ScanEagle requires substantial supporting gear for a UAV launch and retrieval, and NRUAV needs a landing deck, a new concept under development at IAI offers almost every ship, including merchant vessels, a readily deployable option in the Electrically Tethered Observation Platform (ETOP). This is a hovering aerial vehicle that ascends 100 meters (330 ft.) at the press of a button, and offers virtually unlimited mission endurance. ETOP's four lift fans are electrically powered from the ship through the tether, which also carries sensor data back to the ship.