Tank Boat-Antasena X-18 Catamaran Gunboat-An Open Source Intelligence Analysis

De Faakto Intelligence Research Observatory

Image Courtesy of Naval Post.com


Tank Boat-Antasena X-18 Catamaran Gunboat-An Open Source Intelligence Analysis

MethodologyOpen Source Data Research and Intelligence Analysis

Research & AnalysisS.A. Cavanagh

Background & Analysis

The Tank Boat “Antasena” X-18 is an intelligent & cleaver maritime platform built by North Seas Boats in cooperation with the Indonesian Navy. With proper doctrine and deployment this vessel could prove to be a valuable and innovative multi role naval asset. The hull is a light composite fire resistant material which is 10X stronger and 10X lighter than steel. It has a shallow draft of 3 feet which allows for landing of troops, it is 21 feet wide and 59 feet long, providing a good sized deck for personnel and equipment above and below deck. It is capable of launching a surveillance drone(s), a rigid inflatable boat and jet skis for Special Forces missions.  Tank boat has achieved speeds of 40 knots and demonstrates the impressive range of 600 nautical miles on a single fuel load.  The main armament provides the option of a 30mm cannon, or a heavier rifled 105mm cannon. The Cockerill turret system is interchangeable between both cannons and is reconfigurable within hours. The 105 gun is capable of direct fire missions or can elevate like a mortar for, indirect fire support.  The larger gun is able to deliver Cockerill’ Falarick 105 Gun Launched Anti-Tank Guided Missile (GLATGM) which can destroy targets as far as 5000 meters away. The X-18 will have the option of remote operated gun systems in 50 calibre HMG, or 7.62 calibre GPMG. De Faakto analysis suggests a dismountable mortar plate could be fitted on the rear deck to provide 60mm or 120mm mortar support when extra fire power is required.  The large deck space on the aft of the hull is ideal to serve as a fire base for sniper teams and dismountable crew served weapons.  Utility of the available deck space is only limited by the imagination and the payload.  Research literature speculates a missile version of the X-18 will be developed to carry and fire anti-ship missiles. Tank Boat offers a cost effective platform for maritime combat training.  Smaller militaries and navies might purchase a small number of Tank Boats to use for combined arms training.  Nations that have a navy but no marine infantry can familiarize and cross train conventional infantry units for maritime operations, basic seamanship and survival.  Naval officers can work with land combat elements thereby increasing skills, knowledge, and cooperation, while building relationships. Junior infantry platoon commanders and senior NCOs can develop and broaden leadership skills, creating vision for future deployment of resources.

Image Courtesy of Asian Military Review

Why is the Tank Boat Suitable for the Indonesian Navy?

Composed of more than 18,000 islands spread over 8 million km² of waters, the Indonesian archipelago is facing a growing threat coming from piracy and its Chinese neighbor. The continuing deterioration of the security situation in the region put forward the need for a fast, heavily weaponized multirole platform which will be capable to conduct reassurance patrolling, small-scale rescue missions, as well as fire support capabilities for amphibious infantry (Naval News, 2021)


Other Nations Interested in the X-18 Tank Boat

India, Greece, the Philippines and the United Arab Emirates have all expressed interest in acquiring Tank Boats, because they work in similar maritime environments


Who Might Use Tank Boat(s)?

Image Courtesy of merahputih.com

Special Forces

Tank Boat would provide a premium craft for small kinetic strikes and special operations warfare. USN SEALS, Delta Force ODAs, SWCC and MARSOC Marine Raiders could maximize, brown and green water capability using the shallow draft vessel. One of the best assets of tank boats is SOF can rely on their own dedicated fire support when needed or when other forms of close support are unavailable (air cover, naval artillery, heavy machine guns, mortars and drone support).



Tank Boats in the hands of SWCC operators could prove to be a superb asset. With tank boats; SWCC teams can provide a heavy platform firebase for unconventional warfare, infiltration and ex-filtration of platoon size special operations teams. Imagine 1-3 SWCC crews providing maritime over watch in tank boats in a similar fashion as AC 130 gunship do. The extra space provided by the catamaran hull and large deck areas, is useful for other logistical requirements and supports, including command and control, quick reaction forces, and advanced medical surgical.


Maritime Security-Homeland

Tank Boat is capable of various maritime security taskings requiring a flexible naval platform, with landing craft capability.  The X-18 can be used for; homeland security, drug interdiction, human trafficking, fishing enforcement and piracy missions.


Naval Reconnaissance

Tank Boat might be utilized as a platform for clearance divers, maritime survey, navy reconnaissance patrol, and intelligence collection, in regions with vast labyrinths of archipelagos and island chains where opposing forces may choose to hide. Tank Boat with its long range, shallow draft and self sustaining firepower could prove to be a formidable vessel for reconnaissance and intelligence.


Conventional Marine Infantry

Think what X-18 Tank Boat platoons, companies and battalion size squadrons, might look like operating as traditional armored cavalry units might, except on water. Tank boat platoons can be deployed for riverine and island hopping warfare. Infantry supported by heavy machine guns, anti-tank, mortars, cannons and rockets will facilitate landing operations and can provide inland fire missions for troops taking and holding ground.

Image Courtesy of Popular Mechanics

Could the United States Marine Corps Use Tank Boats?

Some naval experts will argue that the Tank Boat concept is not an effective choice for the U.S. Marines. The Marine Corp. is currently reinventing itself so as to operate in the South China Sea, and across island chains such as the Spratlys and Paracels. While a vehicle like Tank Boat sounds like it could be a worthy addition, the Marines would be facing off against the People’s Liberation Army, not pirates or smugglers, and thus require larger ships to carry weapons such as the HIMARS rocket launcher, air defense artillery, and anti-ship missiles. U.S. Marines will also bring their own heavy firepower. Instead of a boat-mounted gun, Marines can call in air strikes with F-35B Joint Strike Fighters, AH-1Z attack helicopters, and 5-inch guns from Navy destroyers. (Popular Mechanics, 2021)  While it is true these assets will provide close combat support for Marines in most instances, there are useful applications for Tank Boat, in the U.S. Navy, Marines and SOF.

Image Courtesy of PT Lundin

What Do Tank Boat Mission Sets, Capabilities and Tactics Look Like?

  • Tank Boat is suitable for anything naval that includes coastal, riverine and inshore operations (Sea Power, 2021)
  • Patrolling and protecting the Indonesia’s maritime domain is a challenge. Indonesia for example is a large and populous country, but is spread out among 17,000 islands, many of them sparsely settled or uninhabited. Critical sea lanes pass through Indonesian waters stretching more than 3,100 miles from West Papua in the east and Aceh in the west (Sea Power, 2021)
  • Indonesia faces two challenges: external defense, which could involve moving troops quickly from one island to the next and internal piracy, which sees organized crime syndicates using the country’s vast web of islands to hide and stage attacks. (Popular Mechanics, 2021)
  • Coast Guard-patrol, search and rescue
  • Hybrid Warfare-South China Sea
  • Maritime Militia
  • Naval Reserve Units and Training
  • Littoral Class Naval Asset-Rivers, Swamps & Coasts
  • Fire Support Craft, close-in and long range artillery support in normally inaccessible coastal areas and rivers
  • Expeditionary and special operations missions operating in shallow water
  • Beach landings to offload or pick up troops
  • In areas with many coastal military bases, the boat can move easily between resupply destinations
  • Tank Boat is able to deploy a RHIB for boarding or SEAL insertion
  • Tank Boat features multi-mission deck for unmanned aircraft
  • The Tank boat is suitable for containerized cargo or modular weapons
  • The boat can deliver logistics & supplies on to dry land
  • It should prove to be adept at transporting military troops to and from the individual islands, and will hopefully also become a powerful deterrent against pirates and organized crime syndicates who utilize the network of coastal waters for illegal activities (Mashable, 2021)
  • Sniper & marksmen teams can operate from the deck areas, provide harassing fire and protect gaps and flanks for landing troops

Image X-18 Antasena concept Missile Boat courtesy of PT Lundin

What Types of Weapons Might be Seen on Future Tank Boats, and what are the Capabilities of these Weapons?

  • The Initial concept of Tank Boat was to feature a Belgian CMI Defense rifled 105mm cannon, instead of the 30mm cannon fitted on the current prototype; therefore it is likely a larger bore gun will be deployed on future Tank Boats (Maritime Executive, 2021)
  • 25 mm gun
  • 50 calibre remotely operated Heavy Machine Gun system
  • EO/IR sensor
  • Belgian CMI Defense rifled 105mm cannon capable of firing the Cockerill Falarick 105 Gun Launched Anti-Tank Guided Missile (GLATGM) able to destroy targets as far as 5000 meters away
  • The X-18 may be equipped with a reconnaissance & surveillance drone system
  • It is speculated a Missile version will be developed which will have anti-ship missiles
  • A 120mm or 60mm mortar system could be mounted on the X-18 platform
  • The X18 can be augmented with a Bofors LEMUR Remote Weapons Systems incorporating 7.62 – GPMG
  • A Tank Boat fitted with Belgium’s CMI Defense 105mm rifled gun as the X18 concept’s proposed main armament is capable of firing high explosive shells and anti-tank shells, at 42-degree elevation which provides the fire support of a mortar or howitzer at non-line of sight targets (Popular Mechanics, 2021)
  • CMI – Cockerill 105mm high-pressure gun mounted in their CT-CV 105HP turret, which integrates an advanced bustle-mounted autoloader to deliver high lethality at very light weight, with a two-person crew, it is able to fire the long-range Falarick 105 Gun-Launched Anti-Tank Guided Missile (GLATGM) and all NATO- standard 105mm types it provides commanders with a wide choice of ammunition to suit the tactical situation. Possessing unusually high +42° gun elevation, this weapon delivers exceptional engagement capability in complex terrain, with indirect-fire HE capability to 10km range, while the GLATGM permits heavy armour to be defeated at ranges in excess of 5 km


Image Soviet WW2 riverine armored boat of 1124 project with a T-34 Turret Courtesy of WIO.RU

Image of Soviet armored boat of 1124 project of Azov military flotilla at Kerch Courtesy of WIO.RU

Image of Project 1204 Shmel-riverine class artillery gun boats Courtesy of World Naval Ships


Image NEMO 120mm Mortar Boat Courtesy of Patria Defense

What Exactly is a Tank Boat?

As the name implies, Tank Boat is the definition of the object; a boat with a tank turret mounted on the hull. The Indonesian Navy “Antasena” X-18 prototype vessel, may appear to be a relatively new concept, however it really is not.  Internet research reveals that, from 1935-1945 the Russian navy built 310 “Riverine Tanks” fitted with T-28 & T-34 tank turrets on projects 1124, 1125 & S40. (WIO.RU, No Date)  These tank boats were sometimes referred to in literature as “Gun Boats” or “Artillery Boats.” The Russian Tank Boat was resurrected again after WW2, with Project 1204 Shmel-class artillery gun boats, which were constructed between 1967-1974. The Shmel-class continues to operate in small numbers today. (Military Factory, 2021)  Another boat formed around a similar concept is the “Mortar Boat” operated by Finland and the United Arab Emirates. The Patria NEMO 120mm mortar boat is a small fast narrow vessel with room for 16 troops in minimal gear. (Jalopnik, 2014) There are two secondary armaments, which consist of 50 calibre heavy machine guns. Below decks is very cramped, and there is a small landing ramp on the bow of the vessel, but the vessel does not provide extra capabilities like the launch able Rigid Hull Inflatable Boat (RHIB) or drone support.  The Patria has a nice armoring package but would not be as effective as the X-18 catamaran given comparable tasks. What is different about the X-18 prototype gun boat compared to its earlier predecessors; is the entire system has been designed around a lightweight catamaran hull which is a more stable platform, made from fire resistant composite materials that are stronger then steel.  When fitted with the armored Cockerill turret, the hull and turret combination offer levels of ballistic protection and fire power of modern armored fighting vehicles. While there are other very capable riverine vessels in many navies around the world, the X-18 is built around the tank gun and turret system, and carries secondary and coaxial armaments much like main battle tanks and armored fighting vehicles.


Image Courtesy of North Sea Boats, PT Pindad and John Cockerill

Meat & Potatoes-Basic Specifications of the X-18

  • High performance 1200 HP diesel powered engines and water jet propulsion
  • Draught of 1 meter or 3 feet
  • Beam of 6.1 meters or 21 feet
  • Length of 18 meters or 59 feet (Defense Post, 2021)
  • Speed 40 knots or 74 kilometers and hour
  • Range 600 nautical miles or 966 kilometers at a speed of 9 knots
  • Crew of 4 or 5
  • Payload of 20 marine infantry although some reports claim Tank Boat is designed to carry up to 60 personnel for landing purposes (Popular Mechanics, 2021)-De Faakto analysis indicates that personnel payload will depend on various factors such as battle loads, and fighting gear; open source information is inconsistent however 20 special forces appears to be the most realistic and quoted capacity with a turret version
  • According to navalnews.com, the APC variant of the Combat Boat is primarily designed for troop transport tasks; it will be capable of carrying up to 60 troops, 5 tons of cargo, drones and will be manned by a 5 strong crew (Navel News, 2021)
  • De Faakto analysis denotes, the APC variant will likely loose the main armament fire support system and function only as a maritime troop carrier
  • The hull is composed of a fire retardant carbon fiber, and uses a two-hull design with a composite material that manufacturers claim is ten times stronger and ten times lighter than steel
  • Propulsion is provided by 1,200hp MAN V8 engines and MJP450 water jets (Defense Post, 2021)
  • Initial cost and development is 10.9 million Euros or 12.9 million US dollars
  • NATO Stanag 4569 Ballistic armor/armor plating covers the whole outside part of bridge & control room


Image Courtesy of Naval News


Specifications for the Cockerill 3030 Turret

Turret-Welded ballistic aluminum, fully Stabilized

Crew-2 crew in the manned version

Main armament-Mk44, MK44S, XM813 Single shot, 5 round burst, full auto, 255-30mm rounds in two-drum feed system

Secondary armament -7,62mm co-axial, pintle mount (7.62, 12.7, 40mm GL), Ammunition loading, external and under armored protection

Anti-tank capability-Turret launched AT Systems

External cameras -360° cover

Gun elevation  -10° / +60°

Ballistic protection-Up to Level 5 STANAG 4569

Protection-8 lance-grenades fumigènes, APS, détection anti-sniper, DAS, FFI, LWD8 smoke grenade launchers, APS, Anti-sniper detection, DAS, FFI, LWD

Sights-Commander/Gunner Sights (Hunter/Killer), Dual axis stabilized, Day/night (John Cockerill, 2021)


Images Courtesy of PT Pindad


Who Makes Tank Boats?

  • PT Pindad, is the Indonesian state-owned company which built & launched the X-18 “Antasena” prototype Tank Boat in April of 2021. Tank Boat finished sea & weapons trials conducted in Banyuwangi, East Java in May of 2021 (Janes, 2021)


 Which Military Contractors Supply Components for Tank Boat?


  • The X-18 carries a John Cockerill 3030 remote turret Protected Weapon Station. Cockerill is a well known manufacturer of turrets for light and medium armoured vehicles; the Belgian company has also made engineering and construction improvements in regards to the marine environment and the specificity of the catamaran composite material (Naval News, 2021)


Main Armament(s)

  • Northrop Grumman has supplied the Mk44 30 mm automatic cannon, housed in the Cockerill turret. The 30mm cannon, is the current main armament used successfully in trials and evaluations
  • Not yet trialed or evaluated, a Tank Boat fitted with Belgium’s CMI Defense 105mm rifled gun was the original concept for the X-18 main armament. Capable of firing high explosive and anti-tank shells, at 42-degrees elevation the 105 provides the versatility of a mortar or a howitzer for non-line of sight targets (Popular Mechanics, 2021)


Secondary Armaments

  • Tank Boat also packs a remote-controlled, 7.62-millimeter general purpose machine gun (Popular Mechanics, 2021)
  • There are two more remote stations, equipped with 50 calibre heavy machine guns mounted in other parts of the craft



  • North Seas Boats, X-18 boasts a fire resistant composite catamaran hull 10X stronger then steel; the design grants stability in addition to a large internal volume, this allows the boat to traverse shallow drafts of three feet or 1 meter (Mashable, 2021)
  • PT Lundin’s North Sea Boats, has experience making composite vessels such as catamarans and landing craft, North Sea Boats built an all-composite trimaran fast attack boat for the Indonesian navy, that was subsequently destroyed in a fire, it appears North Sea Boats learned from this incident and has since engineered fire resistance into their hull composites



  • Communication systems are provided by PT Len Industri Electronics group, the system consists of a crew intercom and a LenHDR100-V high frequency radio, long-distance voice communications and a LenMDR50-V radio, V/UHF radio for tactical data communication


Battlefield Management System

  • PT Hariff is providing Engineering for the Battlefield Management System (BMS)


Video John Cockerill Courtesy of YouTube 




Other Useful Open Source Media Resources

Video John Cockerill Defense-3000 Series Courtesy of YouTube

Video PT Lundin Courtesy of Warthog Defense and YouTube

Video Courtesy of PT Pindad and YouTube


North Sea Boats Detailed Technical Specifications

General Basic Functions-Foil Assisted Catamaran

Hull Material-Infused Vinylester Composite


  • Length Over All 18 m
  • Beam Over All 6.10m
  • Draught 1.00m
  • Propulsion
  • Main Engines 2 x MAN 1200HP
  • Propulsor 2 x MJP450 Waterjet



  • Main Armament Cockerill HP 105mm turret or a Northrop Grumman has supplied the Mk44 30 mm automatic cannon, housed in a Cockerill turret
  • Secondary Armament Lemur RWS 12.7mm – 30mm



  • VHF Radio, SBB Radio and Datalink Option


Navigation and Ship Systems

  • TRANSASS-2 WECDIS stations
  • 1 Radar Station
  • 1 Conning Station
  • 5 Transas WECIDS trackballs
  • 5 Transas WECIDS keyboards
  • 10 24inch Monitors
  • 2 GPS
  • 1 AIS
  • GMDSS A1
  • Double LAN Network with all signals and integration duplicated Weather Station
  • Gyro iXblue
  • Magnetic Compass
  • Autopilot
  • Integration to waterjet, engines, SAFRAN, cameras, CMI, LEMUR RWS



Indonesia Will Patrol Vast Maritime Domain with New Tank Boat-Seapower Magazine-Edward Lundquist (2021) https://seapowermagazine.org/indonesia-will-patrol-vast-maritime-domain-with-new-tank-boat/

Indonesia builds a tank that’s also a boat and names it… Tank Boat-Mashable Sea-Dale John Wong (2021) https://sea.mashable.com/tech/15672/indonesia-builds-a-tank-thats-also-a-boat-and-names-it-tank-boat

Indonesia Developing Amphibious ‘Tank Boats’ for Coastal Patrol- The Defense Post-Joe Saballa(2021)  https://www.thedefensepost.com/2021/05/12/indonesia-boat-tank/

Indonesia Tests “Tank Boat” Patrol Vessel for Island Defense-Maritime Executive- Ankur Kundu (2021) https://www.maritime-executive.com/article/indonesia-tests-tank-boat-patrol-vessel-for-island-defense

Indonesia’s ‘tank boat’ prototype undergoes sea, weapon trials-Janes Intelligence-Gabriel Dominguez & Mark Cazalet (2021)https://www.janes.com/defence-news/news-detail/indonesias-tank-boat-prototype-undergoes-sea-weapon-trials

Indonesia Built a Damn Tank Boat-Popular Mechanics-Kyle Mizokami (2021) https://www.popularmechanics.com/military/weapons/a36354997/indonesia-tank-boat/

Indonesia’s MoD Orders X18 ‘Tank Boat’ Prototype from North Sea Boats-Naval News-Nathan Gain (2021) https://www.navalnews.com/naval-news/2019/05/indonesias-mod-orders-x18-tank-boat-prototype-from-north-sea-boats/

Indonesia’s New X18 Combat Boat Begins On-Water Tests-Naval News-Nathan Gain (2021) https://www.navalnews.com/naval-news/2021/05/indonesias-new-x18-combat-boat-begins-on-water-tests/

John Cockerill Defense (2021) https://johncockerill.com/en/defense-2/

Nautic EXPO (2021) https://pdf.nauticexpo.com/pdf/north-sea-boats/x18-tank-boat/25886-90162.html

North Sea Boats (2021) https://www.ptlundin.com/detailx18.html

THE MOBILE RIVERINE FORCE AS AN EXAMPLE FOR RIVERINE OPS IN THE 21ST CENTURY-CIMSEC-VIA Small Wars Journal-Rick Chersicla (2016) https://cimsec.org/mobile-riverine-force-example-riverine-ops-21st-century/

Soviet WWII armored boats-WIO.ru (No Date) http://wio.ru/fleet/ww2armorb.htm

Shmel-class (Project 1204) Armored Artillery Gunboat / Patrol Boat-1967-Military Factory-Staff Writer (2021) https://www.militaryfactory.com/ships/detail.php?ship_id=shmel-class-artillery-gunboat-soviet-union

The Patria NEMO ‘Mortar Boat’ Is Small And Fast With A Huge Ass Gun-JALOPNIK-Tyler Rogoway (2014) https://jalopnik.com/the-patria-nemo-mortar-boat-is-small-and-fast-with-a-hu-1666492358



Advisory assistance provided by Alan Bryant (USMC) Retired

Editing assistance provided by Chuck Stevens & Milena Castulovich