# The Ocean-Going Autonomous Ship--Challenges and Threats
## 4 The Case of the First Unmanned Ship Crossing the English Channel
### The Voyage  
The vessel has been controlled only from a shore control station (Figure 4b). A K-Mate Autonomy Controller, a product of Kongsberg, was utilized as the shore operator's decision's executor and the G-SAVI Global Situational Awareness via Internet system of Hushcraft Ltd., Essex, UK, provided the operators with the navigational and environmental data. The communication between vessel and shore control station was maintained using the Very Small Aperture Terminal (VSAT) satellite system.  
It should be underscored, that this project was not an autonomous passage, decisions were taken by humans only, although the route followed was executed in autopilot mode. In some cases the course was set by the operator instead of steering to waypoint methods. But full control of the vessel was executed by the software control over the ship's mechanisms with no human element on board, which make this passage a good basis for further analysis towards the autonomy of surface vessels.  
The situation assessment during the passage was based on a radar image, AIS system information, electronic chart and the CCTV images sent to the control station. The functionality of the workstation was very similar to the usual bridge or helmsman desktop on the smaller size vessel. The only difference was the lack of a simple lookout. The crucial part of the watch is to perform a proper data fusion based on electronic device reads. With some limitations of the CCTV image, especially related to the distance estimation, radar becomes the main device for the collision avoidance decisions.  
The CCTV images provide information about objects in the vicinity of the vessel, although the proper recognition of navigational aids and distance estimation is really difficult to perform only based  
Figure 4: The first unmanned crossing from the UK to Belgium: (**a**) The ‘USV Maxlimer’—SEA-KIT type unmanned surface vessel [50]; (**b**) Master Mariner [PERSON] in the shore control station during the transit of the vessel (photo by [PERSON]).  
on CCTV. This is a promising area for the implementation of automated image-processing methods for object detection and the recognition of nautical aids.  
Another issue, which seems to be crucial for the safety of unmanned vessels operation, is a robust and reliable self-diagnosis system on the unmanned vessel to provide the operator with performance quality indicators and an alarm regarding any malfunctions, loss of input data, unforeseen behavior of specific devices or unexpected changes in positioning, speed, heading and attitude measurements systems data.  
Our own experience and numerous discussions with the designer and users of the new class of vessel, which was used for this passage, lead to the conclusion that only the extensive experience of the operators as the crew at sea ensures the seamless transition between a manned vessel's bridge to the unmanned surface vessel control station. This includes the deep understanding of all the relations between sea users with their habits, usual practices and the restrictions on their performance.