Unmanned Systems Technology 038 l Skyeton Raybird-3 l Data storage l Sea-Kit X-Class USV l USVs insight l Spectronik PEM fuel cells l Blue White Robotics UVIO l Antennas l AUVSI Xponential Virtual 2021 report

45 Oceans (GEBCO) training programme in ocean mapping at the Center for Coastal and Ocean Mapping/Joint Hydrographic Center of the University of New Hampshire. The event required competitors to map 500 km 2 or more of seafloor at a depth of 4000 m with no human crew at the scene. The team saw that deploying underwater vehicles and survey systems was the biggest challenge the competition presented, and approached Sea-Kit’s parent company Hushcraft to design a USV capable of launching and recovering a Kongsberg Hugin AUV and that would fit into a 40 ft ISO container. Simpson started Hushcraft with the goal of developing hybrid propulsion systems for large river cruisers, and also worked on advanced low-resistance hull forms for offshore use. Both of these generated useful knowledge for subsequent USV development. “Remote, over-the-horizon AUV deployment had never been achieved before, so this system had to be designed from scratch,” he says, recalling the challenges of the project. “There were also significant obstacles presented by satellite data bandwidth limitations and sending complex situational awareness information from the vessel to the control centre.” The task of taking the combination of vehicles safely offshore, deploying and retrieving the Hugin and updating its mission plans with the USV and AUV being separated by 4 km of water is demanding for many reasons, such as managing a remote launch. Although Kongsberg has its own long- proven Launch and Recovery System (LRS) for the Hugin, that was developed for use aboard relatively large manned vessels, so something suited to remote operation aboard USVs was needed. ‘Treadmill’ LRS Sea-Kit therefore developed its own system, and is in the process of patenting it. The GEBCO-NF alumni team has published a video that shows the rather ingenious invention in action (www. youtube.com/watch?v=FomfAprZ9bM ). The recovery portion of the video shows the Hugin approaching the stern of the X-Class from the point of view of a rear-facing onboard camera. The vessel is trimmed down at the stern under the control of a ballast pumping system to make it easier for the Hugin to enter. The dock has curved sides that help guide the Hugin in as it approaches; the sides have a rubber-like covering to prevent damage to the AUV as it noses its way in and onto a moving rubber belt reminiscent of a gym treadmill. The belt slopes up towards the USV’s bow and also curves into a trough to conform to the Hugin’s rounded hull cross-section before the flexible material flattens out once more when it meets the forward roller. At the sides, the Hugin is guided laterally and held by curved elements with polymer contact surfaces. At the end of its travel, the AUV contacts a curved plate with its nose, cutting the power to the belt and Sea-Kit X-Class | Digest Unmanned Systems Technology | June/July 2021 The X-Class shown trimmed down and with stern doors open to allow the Hugin into the well dock in port (Courtesy of Sea-Kit and Fugro)