• Indonesia is developing a unique boat for so-called “brown water” warfare.
  • The “tank boat” is designed to carry more than 50 troops—and the firepower of a tank.
  • The tank boat will be used to defend the Indonesian archipelago from external threats and pirates.

Is it a tank that floats like a boat, or a boat that shoots like a tank? Indonesia’s new Antasena Tank Boat just might be both.

You love badass military vehicles. So do we. Let’s nerd out over them together.

The long-promised hybrid vehicle is capable of patrolling 600 miles on a single tank of gas—perfect for defending a country made up of thousands of islands. Tank Boat can carry more than a platoon of Indonesian Marines and features a tank-like turret to provide fire support.

After years in development, Tank Boat finally began sea trials off the coast of Banyuwangi, a town in East Java opposite the island of Bali, on April 28, according to the Indonesian defense blog Indomiliter. Indonesia’s Ministry of Defense purchased one Tank Boat from defense contractor PT Lundin and will reportedly buy “lots” if testing is successful.

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Tank Boat as shown includes a 105-millimeter gun turret, .50 caliber remote weapon system, and electro-optical sensor mast.
Tankboat.com

PT Lundin designed Tank Boat with Indonesia’s unique geography in mind. The country of 253 million people is made up of 17,508 islands, with only 6,000 of those islands inhabited. That adds up to a staggering 61,567 miles of coastline—more than five times that of the United States. 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.

Tank Boat is meant to operate in so-called “brown water,” or coastal areas where the land meets the sea. The boat incorporates a catamaran design, which gives it a large internal volume, stability at sea, and a shallow draft of just 3 feet. That shallow draft comes in handy for a boat designed to land troops from the Korps Marinir, Indonesia’s Marine Corps. Tank Boat is designed to carry up to 20 Marines (although some sources say up to 60) for landing purposes. Concept art shows Tank Boat anchoring off a beach and disembarking Marines into shallow water.

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A trade show display of Tank Boat featuring both the 30-millimeter and 105-millimeter gun turrets.
Facebook/Tank Boat

Tank Boat’s dimensions—59 feet long and 21 feet wide—reflect the catamaran hull. The vehicle is equipped with two 1,200-horsepower MAN engines and two waterjets. A foil elevates the hull at higher speeds, reducing drag and giving Tank Boat a top speed of 40 knots. The boat has a maximum range of 600 miles, which means it can travel from Washington D.C. to Boston on a single tank of gas.

None of this is all that unusual for a shallow draft military patrol boat. What makes Tank Boat stand out, of course, is the tank part: a tank-style turret designed to provide fire support for dismounted troops. Indonesian Marines might travel hundreds of miles and fight a battle at the end, using only the weapons they brought with them.

If the Marines travel by Tank Boat, those weapons could include a turret armed with a Cockerill 105-millimeter gun. The gun is capable of firing high explosive shells and anti-tank shells, and its 42-degree elevation gives it the ability to fire like a mortar or howitzer at non-line of sight targets. The gun can even fire the Falarick gun-launched missile, which can engage tanks with a high hit probability out to 3 miles.

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CGI concept art shows the serious firepower Tank Boat packs: 80 Marines wading ashore covered by four 105-millimeter guns and four .50-caliber machine guns.
TankBoat.com

The Tank Boat also packs a remote-controlled, 7.62-millimeter machine gun. That’s a lot of firepower for a 60-foot long boat. The current test boat is armed with a smaller 30-millimeter autocannon, but the larger turret still looks like it’s part of the plan.

Could something like Tank Boat be useful for the U.S. Military? Well, the U.S. Marines are currently reconfiguring to operate in the South China Sea, across island chains such as the Spratlys and Paracels.

But 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—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 heavier supporting firepower: Instead of a boat-mounted gun, Marines could call on air strikes by F-35B Joint Strike Fighters, AH-1Z attack helicopters, and even the 5-inch guns from Navy destroyers.

Regardless, Tank Boat could be a very useful tank—or boat—for the Indonesian military and other armies—or navies—tasked with securing similar countries. The Indonesian Ministry of Defense claims Tank Boat could be operational as early as next year.