# The Ocean-Going Autonomous Ship--Challenges and Threats
## 2 Navigational Equipment and Related Challenges  
An autonomous vessel is nowadays such a novelty that security advisements should be considered more as speculations than scientific analyses. However, it is worth considering various aspects of this issue to reduce the number of aspects where threats may appear. In this context, it is necessary to consider the reliability aspects of all the mechanisms installed on such a ship, because even the simplest failures, such as a blown fuse or a leaky gasket, can cause a serious problem when there is nobody on board to fix it. However, humanity has been able to send unmanned facilities into space for many years and guarantee their long-term exploitation. Therefore, it can be assumed that the theory of reliability is such a developed science that it can solve such a tasks. A separate issue is to ensure the safety of the cargo, but in this paper the authors want to emphasize issues related to navigational aspects of the unmanned ship at full sea. Before analyzing the safety-related aspects of unmanned vessels, some nomenclature should be clarified. In the literature, the word 'autonomous' is often overused, to name all the vehicles with no crew onboard. 'Maritime Autonomous Surface Ships (MASS) UK Code of Practice' [19] recognizes 6 levels of autonomy of the vessel referring to the levels of control, as listed in Table 1. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Level** & **Name** & **Description** \\ \hline
0 & Manned & Vessel/craft is controlled by operators aboard. \\ \hline \multirow{4}{*}{1} & \multirow{4}{*}{Operated} & Under Operated control all cognitive functionality is controlled by the human operator. The operator has direct contact with the unmanned vessel over e.g., continuous radio \\  & & (R/C) and/or cable (e.g., tethered Unmanned Underwater Vehicles—UUVs and Remotely \\  & & Operated Vehicles—ROVs. The operator makes all decisions, directs and controls all \\  & & vehicle and mission functions. \\ \hline \multirow{4}{*}{2} & \multirow{4}{*}{Directed} & Under Directed control some degree of reasoning and ability to respond is implemented \\  & & into the Unmanned Vessel. It may sense the environment, report its state and suggest \\  & & one or several actions. It may also suggest possible actions to the operator, such as e.g., \\ \cline{1-1}  & & prompting the operator for information or decisions. However, the authority to make \\ \cline{1-1}  & & decisions is with the operator. The unmanned vessel will act only if commanded and/or \\ \hline \multirow{4}{*}{3} & \multirow{4}{*}{Delegated} & The unmanned vessel is now authorized to execute some functions. It may sense its \\  & & environment, report its state and define actions, and report its intention. The operator \\ \cline{1-1}  & & has the option to object to (veto) intentions declared by the unmanned vessel during \\ \cline{1-1}  & & a certain time, after which the unmanned vessel will act. the initiative emanates from the \\ \cline{1-1}  & & unmanned vessel and decision-making is shared between the operator and the \\ \hline \multirow{4}{*}{4} & \multirow{4}{*}{Monitored} & The unmanned vessel will sense its environment and report its state. The unmanned \\ \cline{1-1}  & & vessel defines actions, decides, acts and reports its action. The operator may monitor \\ \cline{1-1}  & & the events. \\ \hline \multirow{4}{*}{5} & \multirow{4}{*}{Autonomous} & The unmanned vessel will sense its environment, define possible actions, decide and act. \\ \cline{1-1}  & & The unmanned vessel is afforded a maximum degree of independence and \\ \cline{1-1}  & & self-determination within the context of the system capabilities and limitations. \\ \cline{1-1}  & & Autonomous functions are invoked by the on-board systems at occasions decided by the \\ \cline{1-1}  & & same, without notifying any external units or operators. \\ \hline \hline \end{tabular} The revision of the source document, done in November 2019, didn’t change the approach to the classification of autonomy levels.  
\end{table}