Amphibious Drones: Flying Underwater Machines Changing Defence and Rescue

24 May 2026 · 8 min read

Imagine a drone that can fly over a flooded city, dive into the water to search for survivors, and then surface and take off again — all in a single mission. This isn't science fiction. Amphibious drones — machines that operate in both air and water — are here, and they are already reshaping defence, disaster response, policing, and civil life-saving operations around the world.

A quadcopter drone in flight — the base platform for modern amphibious UAVs.

What Makes a Drone Amphibious?

An amphibious drone is a hybrid aerial-underwater vehicle (HAUV) that can transition between flight and underwater operation. Unlike conventional drones that crash on water contact, these machines are fully sealed, waterproof, and equipped with propulsion systems that work in both air and water.

The core technologies involved are:

Waterproof airframes — Complete sealing of electronics, motors, and batteries against water ingress. Most achieve IP67 or better ratings.

Dual-mode propulsion — Motors that spin propellers efficiently in air and switch to underwater thrust. Some designs use the same motors with reversible-pitch propellers; others use separate dedicated underwater thrusters.

Buoyancy control — Variable ballast systems or thruster-based depth control that allow the drone to hover at any depth, surface on command, or maintain neutral buoyancy for sensor deployment.

Transition mechanics — The hardest challenge. A drone must go from flying (aerodynamic lift) to swimming (buoyant/ thruster-based) without losing stability. Solutions range from the tail-sitting "kingfisher" dive (Nezha-SeaDart) to sealed quadcopters that simply fly into the water (CRACUNS, Avataar).

A NOAA Autonomous Underwater Vehicle — showing the kind of underwater technology that amphibious drones integrate into airborne platforms.

India Leads the Amphibious Drone Race

While much of the world talks about amphibious drones, India is actually building and deploying them.

Avataar by AquaAirX — India's First Amphibious "SEAL Drone"

Developed by Bengaluru-based startup AquaAirX, the Avataar is India's first fully operational amphibious drone. Classified as a "SEAL drone" (Sea, Air, Land), it is a quadcopter that can fly like a conventional UAV, then descend into water and operate underwater. The company has demonstrated real-world transitions from flight to underwater operation and back.

Avataar's potential applications span military reconnaissance (covert littoral surveillance where neither an aircraft nor a boat alone suffices), maritime security, and civilian search-and-rescue.

Sagar Defence Engineering — From USVs to Autonomous Swarms

Pune-based Sagar Defence Engineering, founded by ex-Navy officer Capt Nikunj Parashar, is the leading Indian supplier of unmanned maritime systems. While not strictly amphibious (their drones operate on or under water, not in air), they represent the broader Indian push into two-domain maritime drones:

• 30 Autonomous Underwater Vehicles (AUVs) procured by the Indian Navy (October 2023)
• 12 autonomous weaponized boat swarms ordered for coastal security and Pangong Lake surveillance
• ₹360 crore investment from SKEGEN via the iDEX framework (February 2025)
• Liquid Robotics / Boeing partnership (September 2024) — co-developing Wave Glider USVs for undersea domain awareness, endorsed by PM Modi and President Biden
• India's first Autonomous Maritime Shipbuilding Centre in Andhra Pradesh (March 2026)

The India-US deal specifically mentions a "drone capable of both surface and underwater operations" — an amphibious mandate delivered through the Sagar Defence-Liquid Robotics pipeline.

A Manta UAV launches from the deck of the experimental ship Stiletto — a preview of maritime drone operations that India is now scaling.

Defence Applications — Covert Ops, Port Security, and Anti-Submarine Warfare

Amphibious drones offer military operators something unprecedented: persistent surveillance that seamlessly transitions across domains.

Covert Littoral Reconnaissance

The US Navy's CRACUNS (Corrosion Resistant Aerial Covert Unmanned Nautical System), developed by Johns Hopkins Applied Physics Lab, can be launched from a submerged submarine, fly to shore for reconnaissance, loiter, and then submerge again. This means a submarine can deploy an eye in the sky without surfacing — a fundamental shift in covert operations.

Mine Countermeasures

The surf zone — where waves break on a beach — is the most dangerous environment for naval operations. Amphibious drones can fly over the area, dive to inspect suspicious objects, and mark mines for disposal, all without risking human divers or expensive mine-hunting vessels.

Port and Harbour Security

A single amphibious drone can patrol a port from above, then descend to inspect ship hulls for limpet mines or contraband, combining two missions that previously required separate aerial and underwater assets.

Anti-Submarine Warfare (ASW)

Persistent hybrid platforms like the Wave Glider (being brought to India through the Sagar Defence-Boeing partnership) can loiter for months at sea, using underwater acoustic sensors to track submarines while maintaining satellite communication for real-time data relay.

Unmanned surface vehicles (USVs) have proven their combat value in Ukraine. Amphibious drones take this concept further by adding aerial capability.

Disaster Management & Life-Saving

This is where amphibious drones could have the most immediate human impact.

Flood Rescue

When rivers overflow and cities become canals, conventional drones can spot survivors from above — but they can't reach them in the water. An amphibious drone can fly to a stranded person, land on the water, and deliver a flotation device or life vest, then take off again to reach the next victim. In India, where monsoon floods displace millions annually, this capability could save thousands of lives.

Maritime Search and Rescue

China's Nezha-SeaDart, developed by Shanghai Jiao Tong University, has been specifically tested for marine search and rescue. The tail-sitting eVTOL can hover like a drone, fly like a fixed-wing aircraft for rapid wide-area search, and then dive nose-first underwater like a kingfisher to inspect submerged wreckage or locate victims. It can even tow divers underwater to specific locations.

Offshore Platform Emergencies

Russia's Chirok amphibious UAV (700kg MTOW, 300kg payload, 2,500km range) was specifically designed for delivering supplies to distant oil rigs. In an emergency, an amphibious drone could inspect a rig's underwater structure for damage, deliver life-saving equipment, or provide real-time situational awareness to rescue coordinators.

Dam and Levee Inspection

After a natural disaster, dams and levees need both aerial inspection (above-water cracks) and underwater inspection (scour damage at the base). Amphibious drones can do both in a single autonomous mission, cutting inspection time from days to hours.

Commercial Life-Saving — Splashdrone

On the commercial side, SwellPro's Splashdrone family — IP67 waterproof quadcopters that can land on and take off from water — are already deployed by civil SAR teams, coast guard units, and lifeguard services worldwide for:

• Dropping life rings to swimmers in rip currents
• Beach patrol and shark spotting with water-landing capability
• Delivering emergency communication devices to stranded boaters

India's Matangi autonomous vessel — showing the kind of unmanned maritime capability that India is actively developing and deploying.

Policing and Civil Applications

Coastal Border Patrol

An amphibious drone tracking a smuggler's boat can follow it from the air, land on the water if the boat enters a marina or enclosed dock, and continue monitoring from the water surface — maintaining contact when a purely aerial drone would lose visual cover.

Evidence Recovery

When a weapon or phone is thrown into a river or lake during a crime, recovery traditionally requires dive teams with all their logistical overhead. An amphibious drone can fly to the location, submerge to search the area, and retrieve or mark the evidence — all in under 30 minutes.

Fisheries Enforcement

Monitoring illegal fishing from above works well for spotting boats, but proving a net is illegal often requires underwater inspection. An amphibious drone can fly to a suspect vessel, dive to inspect the net mesh size and catch, and surface with photographic evidence.

Security in Flooded Areas

When a city is flooded, amphibious drones can patrol submerged neighbourhoods for looting, deliver supplies to stranded residents, and maintain communication relay — all while transitioning between air and water as conditions require.

The Global Landscape

The Road Ahead

Amphibious drones sit at the intersection of three fast-maturing technologies: waterproof electronics powerful enough to fly, compact underwater thrusters, and AI navigation systems smart enough to handle the transition between air and water.

The next five years will likely see:

• Standardised amphibious platforms adopted by coast guards and navies worldwide
• Autonomous swarm missions where groups of amphibious drones coordinate across air and water domains
• Commercial SAR teams deploying amphibious drones as standard equipment, replacing separate aerial and underwater search assets
• Indian leadership growing through Sagar Defence's pipeline and AquaAirX's innovation

For a country like India — with 7,500 km of coastline, monsoon floods every year, and a strategic need for maritime domain awareness — amphibious drones aren't a luxury. They're a necessity whose time has come.