# Costs and Benefits of Autonomous Shipping--A Literature Review
## 1 Introduction  
Recently, we can observe a continuously growing trend worldwide in research and development of autonomous ships in academia, industry, and maritime authorities. As per International Maritime Organization [1], autonomous ships are referred to as Maritime Autonomous Surface Ships (MASS). They are expected to operate in one of four degrees of autonomy, dynamically switching between them, as presented in Table 1. The classification was prepared only for a regulatory scoping exercise aimed at identifying legal barriers to MASS implementation, but is also used for other purposes [2, 3].Currently, the autonomous ships are not allowed for international shipping due to law regulations [4, 5, 6, 7]. \begin{table}
\begin{tabular}{c c} \hline \hline  & **Degree of Autonomy** & **Description** \\ \hline
1. & Ship with automated processes and decision support & Seafarers are on board to operate and control shipboard systems and functions. Some operations may be automated. \\
2. & Remotely controlled ship with & The ship is controlled and operated from another location, but seafarers are on board. \\
3. & Remotely controlled ship without & The ship is controlled and operated from another location. There are no seafarers on board. \\
4. & Fully autonomous ship & The operating system of the ship is able to make decisions and determine actions by itself. \\ \hline \hline \end{tabular}
\end{table} 
Table 1: The degree of autonomy and description presented by IMO [1]. The first degree refers to a manned vessel fitted with advanced systems that automate propulsion and guidance of the ship, thus, reducing crews' mental workload [8]. Controlling the ship from another location introduces the need to implement the Shore Control Centre (SCC), which is responsible for the vessel navigation as well as other aspects of her operations. In case of a remotely controlled ship with seafarers on board--degree 2--the crew is responsible for entering and departing ports as well as for trouble-shooting. The same can arguably be achieved remotely under degree 3. [PERSON] claims that, to achieve the economic feasibility, the full autonomy--degree 4--shall be exploited to the greatest extent possible [9; 10]. The introduction of MASS into the operation is mainly related to the assessment of the economic benefits of them, simultaneously ensuring the proper level of safety [11; 12; 13]. One of the key issues for shipowners is the cost-effectiveness of the implemented solution and the scale of its benefits. If the implementation of autonomous ships does not bring sufficient economic benefits, shipping companies most likely will not be interested in investing in such solutions due to the low ROI (Return On Investment). Innovative solutions are usually associated with a greater uncertainty concerning their outcome, thus, implying higher risks and a need for managing the latter [14], especially in the low-margin shipping industry [15]. Up to date, there have been several international Research and Development projects concerning multi-faceted benefits of implementing the autonomous ships into operation [16]. They outlined different scenarios for operating an autonomous ship. For instance, a concept developed in the course of the MUNIN project involved crew participation in entering and departing the port, while the ocean-passage was to be carried out autonomously [16]. Therein, a medium-sized bulk carrier involved in worldwide trade was considered, and the economic analysis performed accounted for these kinds of shipping scenarios. Another example is a ReVolt project, where an autonomous ship prototype was designed by DNV-GL [17]. The motivation for this concept was somewhat different than in MUNIN, since it focuses on coastal waters and the solution developed aimed at the reduction of traffic congestion in urban areas and operating costs of road transport. The overall goal was to move the freight volume from roads to short-sea-shipping (SSS) [17].