USE Network launch I UAV Works VALAQ l Cable harnesses l USVs insight l Xponential 2020 update l MARIN AUV l Suter Industries TOA 288 l Vitirover l AI systems l Vtrus ABI

50 158 kg, with 90 kg spare for integrating acoustic survey payloads such as the Teledyne Reson SeaBat T50 and T20, or the R2Sonic 2024. “The idea was to have a USV that would pierce the waves and so ride through heavier sea states more smoothly,” says John Tamplin, CEO of Seafloor Systems. “That’s really important for ensuring the payload under the boat doesn’t plane out of the water and suffer a load of acoustic interference, as that severely impacts the quality of hydrographic data. “Myers started by using established theory on wave-piercing hulls, but as he continued the project he fitted the hull more closely to our applications. When the EchoBoat-240 is traversing from inshore to offshore, or it’s on a river with strong currents and rapids, it needs to constantly change speed and acceleration, and to get up on a plane at higher speeds. The hull design reflects that.” In normal operations, the USV’s two brushless DC outboard thrusters enable a cruising speed of 3-4 knots (5 knots top speed), which allows an endurance of about 8 hours. Two of the primary anticipated users of the vessel are the US Army Corps of Engineers (USACE) and the National Oceanic and Atmospheric Administration. Both are experienced USV operators who regularly trial a variety of marine unmanned systems for critical technical programmes. “The EchoBoat-240 will provide a new offshore capability for them in that vein,” Tamplin adds. “USACE does a lot of surveys in the San Francisco bay, but it has this stretch that goes about 7 miles out into the ocean. It specifically wanted a USV that could operate for up to 8 hours and be trusted to safely traverse from the port to that offshore region at up to 5 knots.” Like Seafloor’s other USVs, the EchoBoat- 240’s hull is rotation-moulded (or ‘roto- moulded’) using high-density polyethylene. In roto-moulding, an aluminium or steel mould of the hull is created, and pellets of the polyethylene are injected inside it. The mould is then superheated while being lifted and rotated in multiple axes by a crane-like mechanical arm. As the polyethylene melts inside the mould, the rotation causes it to disperse and stick evenly across the inner walls of the mould. That helps to maintain a balanced material thickness throughout the hull and significantly lowers the risk of sagging and deformations as the polyethylene cools. “Compared with other conventional approaches to thermoplastic USV designs, such as injection moulding two parts and bonding them together, our material and fabrication method makes the USV far less fragile,” Tamplin says. “Autonomy for long-endurance boats naturally depends on them lasting a long time,” he adds. “We don’t want our USVs to split apart from smacking into a rock, so we want to make sure our fabrication process leads to really rugged hull structures.” Defence In another innovation for maritime autonomy, UAV Navigation has adapted its Vector autopilot system for USVs. This followed a request from Sistemas de Control Remoto (SCR), which makes target drone aircraft and is a UAV Navigation client, to create the autonomy for two testbed vehicles being developed June/July 2020 | Unmanned Systems Technology The Spayke II USV from Sistemas de Control Remoto has been equipped with UAV Navigation’s Vector autopilot – reconfigured for USV operations – and trialled in operations with the Spanish navy (Courtesy of UAV Navigation and SCR)