Marines 3D Print a 7-Meter Raiding Craft in Okinawa

Marines in Okinawa turned a large-format polymer 3D printer into a boatyard during Exercise Valiant Shield 26. On June 29, Intermediate Repair Company, 3rd Maintenance Battalion, 3rd Marine Logistics Group, launched a 7-meter foam hull raiding craft at White Beach Naval Facility. The vessel ran both manned and unmanned missions, including autonomous waypoint navigation.

How they built it

The team used three main tools: a computer numerical control router, a large-format polymer 3D printer, and a spray foam and coating system. Materials were chosen for worldwide availability so units could source them locally if needed. That matters across the vast Pacific, where waiting for a replacement craft can take weeks.

A previous 5-meter prototype required about 16 working hours and roughly $11,000 in materials. The team believes a scaled production line with 12 people could turn out a 5-meter platform every four hours and a 7-meter platform every six hours. Those numbers are still estimates, but the demonstration proved the concept works.

RAMFORCE and the bigger goal

The craft was the most visible output of Resilient Advanced Manufacturing For Contested Environments, or RAMFORCE. The initiative, hosted by the Office of the Under Secretary for Research and Engineering, tested whether expeditionary forces can repair, replace, and produce equipment without waiting on traditional supply chains.

Marines also ran a parallel experiment called Print on the Move. They tested whether commercially available polymer 3D printers could keep fabricating parts while bouncing along on tactical vehicles and watercraft. One printer continued working during the transit to White Beach and even while aboard the foam craft as it operated on the water.

Why it matters

The Marine Corps has been pushing additive manufacturing down to the unit level for some time. Smaller 3D printers already produce custom tools, brackets, drone components, and replacement parts that would otherwise sit in supply channels for weeks or months. The RAMFORCE demonstration scales that idea up to major equipment.

Major Daniel Krake, commander of Intermediate Repair Company, put it plainly: RAMFORCE is not just about advanced manufacturing; it is about integration. The equipment and partnerships from the exercise stayed with the unit afterward so they can keep refining the capability. Senior leaders from III Marine Expeditionary Force and 3rd MLG watched the White Beach demonstration firsthand.

For a force operating across the First Island Chain, the difference between mission success and failure can come down to whether a broken part or missing platform can be built before the adversary can act. That is the problem this kind of in-theater manufacturing is meant to solve.