U.S. Navy Orders and Tests Armed TSUNAMI Uncrewed Surface Vessels for SOUTHCOM Maritime Missions.

Textron Systems will deliver multiple TSUNAMI uncrewed surface vessels to U.S. Southern Command and U.S. Navy Fourth Fleet for Fleet Experimentation 2026, giving U.S. forces a rapidly deployable autonomous platform for maritime surveillance, interdiction support, and manned-unmanned surface warfare operations in contested coastal waters. The contract, announced on April 30, 2026, strengthens persistent monitoring and rapid response capacity in a region where tracking illicit trafficking, irregular maritime activity, and dispersed threats remains a constant operational challenge.

The deployment includes TSUNAMI 25 Long Dwell Interceptor vessels supported by field service representatives, with delivery completed within three weeks of contract award ahead of trials in Key West and follow-on operations near Comalapa, El Salvador. The platform’s long-endurance autonomous capability expands the Navy’s ability to sustain surveillance and distributed maritime operations with lower manpower requirements, reflecting the growing role of unmanned systems in regional security and future naval warfare.

Related topic: U.S. Textron Arms CUSV Drone Boat With BRAWLR Launcher To Extend Fleet Air Defense Coverage At Sea.

Textron Systems' TSUNAMI 25 uncrewed surface vessel will support U.S. Navy Fourth Fleet and SOUTHCOM trials in Key West, combining high-speed maritime surveillance, autonomous interdiction support, and potential precision armament for counter-drug and littoral security missions (Picture source: U.S. DoW).

The TSUNAMI 25 is a 25 ft uncrewed surface vessel with a 9 ft beam, a 400 hp engine, a maximum weight capacity of 3,642 lb, and a listed top speed above 40 kt. These figures place it in the fast interceptor class rather than the endurance-only surveillance category: the vessel is large enough to carry sensors, communications equipment, and mission payloads, but small enough to be deployed in numbers and operated around ports, littoral waters, and interdiction boxes where a destroyer or cutter would be an inefficient use of capacity. Textron’s wider TSUNAMI family ranges from 21 ft to 38 ft, with the largest variant using three 400 hp engines, carrying up to 5,214 lb, and exceeding 50 kt, which indicates a design path from light patrol craft to heavier sensor or weapon configurations.

TSUNAMI is not a clean-sheet naval hull. Textron built the family around Brunswick Corporation commercial vessels and added its CUSV autonomy control system, derived from the Common Unmanned Surface Vehicle work used in U.S. Navy mine countermeasure programs. That matters for cost and availability: commercial boat production reduces the time needed to obtain hulls, while the autonomy package provides route execution, remote control, and payload integration. For Congress and naval planners, the relevant question is not whether one TSUNAMI can replace a crewed patrol vessel; it cannot. The question is whether a group of lower-cost autonomous craft can absorb surveillance hours, maintain contact with suspect vessels, and reduce the number of times scarce crewed ships must be diverted from higher-value missions.

The armament issue is centered on Invariant Corporation’s Surface-to-Air Kinetic Engagement system, known as STAKE, which was integrated on a Textron TSUNAMI vessel for early testing at Lake Guntersville, Alabama, in February 2026. STAKE is a modular counter-uncrewed-systems weapon set built around two subsystems: Hunter, which carries the sensor and laser designation package for acquiring and tracking targets, and Killer, which provides the precision engagement function. The military significance is the separation of detection, designation, and firing into a compact package that can be mounted on a small surface vessel and operated within a controlled kill chain. It is a way to test whether a robotic surface craft can contribute to local air defense or close-in surface defense without requiring a full ship combat system.

STAKE’s reported use of the Advanced Precision Kill Weapon System gives the TSUNAMI trial a concrete weapons basis rather than a generic “armed drone” concept. APKWS converts the 2.75 in Hydra rocket into a laser-guided munition by inserting a guidance section between the legacy 10 lb high-explosive warhead and the Mk66 Mod 4 rocket motor. The all-up round is 73.77 in long, 2.75 in in diameter, and weighs 32.6 lb, with a maximum speed of 1,000 m/s and M151 or Mk152 high-explosive warheads. The guidance kit uses Distributed Aperture Semi-Active Laser Seeker optics on four deployable wings and can lock onto moving or stationary targets, with counter-UAV and ground-launched applications already part of the weapon’s development path.

For a TSUNAMI-class vessel, an APKWS-based armament would be most relevant against small unmanned aerial vehicles, lightly built hostile craft, exposed sensors, or engines rather than hardened naval targets. The 70 mm rocket offers a smaller warhead than anti-ship missiles and can be carried in greater numbers, which is important in cluttered coastal waters where proportionality, identification, and collateral damage are practical constraints. The limitation is equally clear: the weapon depends on reliable target identification, laser designation, communications, and rules-of-engagement control. In operational terms, the vessel’s value would come from being one node in a supervised sensor-to-shooter chain, not from independent lethal decision-making.

The air-surface pairing tested at FLEX 2026 is central to that chain. TSUNAMI is being used to demonstrate cooperative intelligence, surveillance, reconnaissance, and targeting with the Aerosonde 4.7 VTOL unmanned aerial vehicle from a littoral combat ship. The Aerosonde 4.7 VTOL carries up to 23 lb of payload, has a 14.45 ft wingspan, a 140 km range, 9 hours of endurance, and vertical takeoff and landing capability. In practical terms, the aircraft can search beyond the surface vessel’s radar and visual horizon, while TSUNAMI can move toward the contact, relay closer imagery, and help maintain custody until a helicopter, cutter, boarding team, or partner-nation vessel arrives.

The U.S. Navy needs these drones because Fourth Fleet’s mission area is large, maritime, and manpower-intensive. SOUTHCOM’s area of responsibility covers 31 countries, 12 dependencies and areas of special sovereignty, the Caribbean Sea, the waters adjacent to Central and South America, and Latin America south of Mexico. Joint Interagency Task Force South, a SOUTHCOM component, is tasked with using all-domain capabilities with partner nations to detect and monitor illicit trafficking in the air and maritime domains, enabling interdiction and apprehension. That mission creates a persistent demand for sensors and contact-tracking assets that is disproportionate to the number of crewed naval vessels normally assigned to the region.

FLEX 2026, therefore, should be read as an operational evaluation rather than a technology display. The Key West event integrated commercially developed unmanned systems and artificial intelligence with USS Wichita, an MH-60 helicopter, and other manned assets to find, track, target, and engage captured drug boats. The synchronized force included uncrewed aerial vehicles, uncrewed surface vessels, helicopters, and a Freedom-class littoral combat ship, with the scenario including law-enforcement interdiction and kinetic engagements against captured drug boats. The Navy is using real maritime-security missions to test robotic integration before applying the lessons to more contested theaters.

The immediate benefit for Fourth Fleet is additional presence at lower personnel risk; the longer-term issue is whether the Navy can turn small autonomous vessels into reliable, supportable, and legally controlled parts of routine operations. TSUNAMI offers speed, payload margin, and commercial manufacturability, but the decisive factors will be communications resilience, maintenance burden, operator workload, identification standards, and the command authority governing any armed engagement. If those issues are solved in SOUTHCOM’s demanding but lower-end maritime environment, the same operating model could support harbor defense, convoy escort, counter-UAV screening, and distributed sensing in higher-threat regions. The contract is relevant because it shows the U.S. Navy testing armed and unarmed robotic vessels in a mission area where operational demand, not demonstration value, will determine whether the concept is retained.

Written by Evan Lerouvillois, Defense Analyst.

Evan studied International Relations, and quickly specialized in defense and security. He is particularly interested in the influence of the defense sector on global geopolitics, and analyzes how technological innovations in defense, arms export contracts, and military strategies influence the international geopolitical scene.