Page 10: of Marine Technology Magazine (November 2025)

SUBSEA DEFENSE UNMANNED SYSTEMS the F4 can provide a rapidly deployable, targeted sensing or HORUS can achieve sailing speeds of 0.5 to 2.5 knots under communication capability at dramatically reduced cost and wind power and up to 4 knots using its electric thruster for sta- logistical overhead. tion-keeping or low-wind transit. With the Defense Innovation

Some intriguing recreational COTS systems also offer de- Unit supporting the vehicle’s transition to contract manufac- fense potential. Chinese manufacturer SwellPro has carved turing, HORUS represents a next-generation approach to scal- out a niche with its SplashDrone 4, a self-righting, rugge- able, “disruptively affordable” autonomous maritime systems.

dized, fully waterproof quadcopter that can ? y, land, ? oat on SubSeaSail’s HERMES, meanwhile, is a scalable, self-right- water, and take off again. And then there’s the HOVERAir ing, semi-submersible trimaran designed for long-duration

Aqua, a pocket-sized, IP67-rated drone by Zero Zero Ro- surface and subsurface operations, and is envisioned as a car- botics, makers of the popular HOVERAir self-? ying camera go and expeditionary power supply platform. Like HORUS, drone. The Aqua can ? oat, stabilize, and even ? lm below the HERMES can submerge to 100 meters to evade detection or ocean surface in “Snorkel Mode” using its tilting 4K camera. ride out severe weather. With speeds of 5 to 15 knots, and

While neither vehicle dives fully beneath the waves, they large-volume payload space, it offers a high-speed, attritable demonstrate how quickly amphibious UAS are maturing in platform for contested logistics.

the commercial space, and could readily be adapted for mar- Another maritime innovator, Gulfport-based Ocean Aero, itime drone operations. has developed a ? rst-of-its-kind hybrid autonomous platform, the Triton. Measuring approximately 4.5 meters in length and

Surface to Undersea: Piercing the Interface weighing 350 kilograms, its folding rigid sail, integrated solar

Imagine an autonomous vehicle that can operate both above panels, and electric drive enable months-long surface opera- and below the ocean surface, combining the persistence and tions or dives to 200 meters for up to ? ve days. In addition to communication advantages of a USV with the stealth capa- surface surveillance, the Triton’s body payload capacity of 23 bilities of a UUV. Now imagine it is powered exclusively by kilograms (with additional space in the wing and keel) enables wind and solar energy, and can be organized into distributed, underwater survey and intelligence operations, making it well high-endurance, attritable ? eets for full-spectrum maritime suited for missions such as anti-submarine warfare (ASW), surveillance. mine countermeasures (MCM), and critical infrastructure pro-

San Diego-based SubSeaSail has spent nearly a decade tection. The vehicle is designed for one or two-person launch/ perfecting just such a vehicle. HORUS is a compact, light- recovery from ship or shore, and a small logistics footprint weight, monohull AUSV designed for persistent maritime op- allows it to be easily transported and deployed in remote or erations and data collection. A patented, transparent wingsail contested regions.

enables low-signature operations at sea for months without On the higher displacement end of the spectrum, the Lei- fuel or maintenance, while its ability to submerge to depths dos Sea Specter is an autonomous low-pro? le vessel (ALPV) of 100 meters allows it to evade detection or adverse weather developed for the U.S. Marine Corps to support distributed conditions. Measuring approximately 1.6 meters in length operations and contested logistics. Inspired by semi-sub- and weighing around 32 kilograms in its base con? guration, mersible “narco-boats,” the 65-foot diesel-powered craft rides low in the water to minimize visual, radar, and infra- red signatures. Designed to carry up to ? ve tons of cargo at speeds of eight knots and ranges exceeding 2,000 nautical

THE HOVERAIRAQUA miles, it offers a stealthy, attritable platform for clandestine supply chains. A prototype is already undergoing ? eld test- ing in Okinawa, where Marine Corps Combat Logistics Bat- talion 31 and the 12th Littoral Logistics Battalion are putting the vessel through its paces.

A Vanishing Divide

The ocean surface is increasingly a ? exible membrane through which platforms can transit at will, and as autonomy continues to advance, the distinctions among air, surface, and underwater domains may blur. Future strike groups may be accompanied not only by ? eets of heterogenous drones, but an array of clever and capable hybrids - vehicles that can ? y, sail, dive, and relay information seamlessly across domains. The erosion of ? xed maritime boundaries is under- way, and could usher in a more ? uid, adaptive, and intercon- nected battlespace.

Credit: HOVERAir 10 November/December 2025

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