# Sensing in Inland Waters to Promote Safe Navigation: A Case Study in the Aveiro's Lagoon
## 3 Low-Cost Maritime Data-Sharing System Design and Evaluation
### Techniques for Supporting Maritime Information Sharing and Visualization: A Benchmarking Analysis
Regarding data representation using a single interface, Saillogger [71] and SaillRacer [74] offer several advantages over other applications and services. These two apps synthesize key data to reduce sailors' cognitive load and streamline the decision-making process. Moreover, in the case of Saillogger, the cost of the equipment is lower than the average for the applications analyzed. Meanwhile, Savvy Navvy maintains visual coherence in its interface, offering intuitive graphics and detailed application guides. Investigating the e-Paper technologies mentioned in SaillRacer [74] may address the limitations encountered during data communication and visualization in maritime contexts. Throughout this benchmarking, the primary data presented across interfaces of the analyzed systems and applications included water and ground speed, position, current, depth, wind, and vessel heading. Table 2 summarizes an analysis of the key functionalities that needed to be integrated into the maritime sharing system developed. These criteria consider whether the analyzed services connect with boat sensors to minimize implementation costs and ensure visual consistency and ease of use in maritime contexts. Furthermore, following an exhaustive examination of the available technological solutions and electronic components, it was determined that Raspberry Pi is a highly versatile device with a competitive price point in comparison to the various solutions \begin{table}
\begin{tabular}{p{42.7 pt} p{42.7 pt} p{42.7 pt} p{42.7 pt} p{42.7 pt} p{42.7 pt} p{42.7 pt} p{42.7 pt}} \hline \hline
**C Criteria** & \begin{tabular}{c} **Bot Sensor** \\ **Connectivity** \\ \end{tabular} & **Inland Water Data** & \begin{tabular}{c} **Friendly UI** \\ **Design** \\ \end{tabular} & \begin{tabular}{c} **SVLFriendly** \\ **Interface** \\ \end{tabular} & \
\begin{tabular}{c} **Community** \\ **Data-Sharing** \\ \end{tabular} &
\begin{tabular}{c} **Free** \\ **Software Access** \\ \end{tabular} & **Price in Euros** \\ \hline Saillogger [71] & ✓ & & & & & & & App is Free, but requires a specific hardware that costs 25 EUR-350 \\ \hline Nebo [72] & & & & & & & 183.66 EUR \\ \hline PredieWind: DataHub [9] & ✓ & & ✓ & ✓ & ✓ & & & Arp requires a suggestion to access to the main functionalities, and specific, hardware that costs 279 EUR \\ \hline Maritime data sharing system developed by the authors & ✓ & ✓ & ✓ & ✓ & ✓ & ✓ & 164.25 EUR \\ \hline \hline \end{tabular}
\end{table} 
Table 2: _Cont._currently on the market, presently costing around EUR 62. To further enhance the system, a 7\" Raspberry Pi touchscreen was also acquired at a cost of around EUR 73, and a case to safeguard the system was acquired at a cost of around EUR 8. Furthermore, the ESP8266 is a cost-effective microcontroller, priced at around EUR 8, with fundamental capabilities for integration into an IoT network. In this regard, the total cost of the system, including the memory card, two heatsinks, and a power cable, amounted to around EUR 164. Based on the findings of this research, the system's cost is relatively affordable, as it incorporates essential features for navigation in various environments, including inland and coastal waters, which are lacking in other solutions. The benchmarking study provided valuable insights that were essential to the preparation of the data collection process regarding the crucial data that needed to be shared within the low-cost maritime data sharing system. Moreover, this comparative study contributed to supporting the conceptualization of the maritime data sharing UI.