Grey Whale G1 Offshore Test: Stable 11 m Hover, 12 km Out

Twelve kilometers offshore, a drone descends step by step from 80 m to just 11 m above the sea surface. Under remote beyond-visual-line-of-sight (BVLOS) control, can it maintain its communication link and hold a stable hover?

Purple Swallow Tech's Grey Whale G1 transport unmanned helicopter recently completed a dedicated offshore BVLOS altitude descent test. The aircraft descended continuously from 80 m to 11 m and held a stable hover 11 m above the sea surface.

The Grey Whale G1 is a fully electric unmanned helicopter purpose-built by Purple Swallow Tech for low-altitude logistics in complex environments. It carries a 15 kg payload, withstands Level 8 winds, and holds a special airworthiness certificate for medium unmanned helicopters. This test focused on its communication and low-altitude flight performance in the marine environment.

Long-Range Communication: Stable Data Relay 12 km Offshore

Offshore BVLOS operations demand continuous visibility into flight status and on-site conditions.

This test was conducted 12 km offshore under full remote BVLOS control. Throughout the descent and hover, images and flight data were relayed reliably, giving operators the information they needed to monitor the flight and assess conditions on site.

Ultra-Low-Altitude Control: From 80 m to 11 m, a Stable Hover

Near the sea surface, the aircraft must contend with localized air currents and wave disturbance. In this test, the Grey Whale G1 descended step by step from a baseline altitude of 80 m and finally hovered 11 m above the sea. The descent was smooth, and no noticeable oscillation or drift occurred during the hover.

The flight demonstrated the Grey Whale G1's low-altitude attitude control capability under the sea state and test configuration used here.

11 m was the hover altitude for this test; actual operations must set altitude based on the environment, payload, and safety requirements.

Built for Maritime Missions: From Flight Validation to Task Application

Long-range connectivity and stable station-keeping close to the sea surface give mission payloads a platform for observation, detection, and data relay. To meet maritime operational needs, the Grey Whale G1 can be further adapted for:

• Offshore aquaculture — Inspection of cages and surrounding waters, and facility documentation; with dedicated payloads, exploration of fish-finding and underwater mapping.

• Offshore energy O&M — Observation support for offshore facilities, plus adaptation of subsea pipeline inspection solutions in combination with underwater detection equipment or collaborative systems.

• Maritime search and rescue — Target search and image relay using suitable electro-optical payloads, providing information support for locating people overboard and coordinating rescue efforts.

  
  

Conclusion

From long-range connectivity offshore to descent and hover near the sea surface, this test has built real-world evidence for adapting the Grey Whale G1 to maritime scenarios. Purple Swallow Tech will continue advancing payload adaptation and mission validation around offshore aquaculture, maritime supervision, and offshore energy O&M requirements.

Industry partners are welcome to engage with us on site surveys, flight-test evaluation, and scenario customization.