# 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  
To inform the design and implementation of the data sharing system in this study, an understanding of current maritime technologies is essential. Therefore, a comparative study, known as benchmarking, was performed. Benchmarking is a useful approach for comparing practices and products developed by competitors, aiming to identify gaps in existing solutions that could be addressed by research [52; 53; 54]. A benchmarking process was conducted to identify and compare several navigation support systems, including proof of concepts, nautical applications, and equipment such as _chartplotters_ and AIS, developed both academically and industrially. Each of these solutions aligns with the objectives outlined for this research:  
* Solutions facilitating real-time data sharing and visualization with other users;
* Solutions representing meteoceanographic conditions and navigational information along maritime routes. This study builds on a previous benchmarking study of mobile nautical applications [55]; however, it was updated to focus on developing the presented low-cost IoT solution. A comparison with commercially certified devices is valuable for understanding the state-of the art in both functionality and UI design. By analyzing these established products, key features that are essential for similar systems can be identified. This comparison ensures that the system not only meets functional requirements but also adheres to UI conventions commonly used in maritime applications. By maintaining these established standards, a fluid user experience can be ensured, allowing navigators to interact with the interface comfortably and effectively as they are already accustomed some of these common practices. The identification of solutions was carried out by searching across mobile application stores, such as the App Store and Play Store, scholarly databases, such as IEEE Explore, Scopus, and Web of Science, Facebook groups, and a general Google search using terms, such as \"data sharing systems to support maritime navigation\", \"sharing data from marine navigation devices\", \"maritime navigation devices sharing information\", and \"NMEA usage to sharing navigation devices data\". Eighteen technological solutions, including mobile applications and navigation support tools, were thoroughly examined to determine how they can be used to share meteoceanographic data and verify if those services could incorporate important information to improve maritime safety, such as updated signalization data, cartography, and bathymetric data. This research has contributed to improving the evaluation of maritime technologies by offering new perspectives and has offered important insights into the effectiveness, advantages, weaknesses, innovation, and cost-effectiveness of these solutions. Currently, the maritime community can make use of a variety of tools to access pertinent information that assists in navigation, which can be acquired through (i) sensors situated in the maritime environment that transmit data to a central hub and subsequently disseminate it to sailors [56] or (ii) sensors installed on the navigators' vessels that allow sailors to share relevant data [57; 58]. However, the first type of solutions, such as smart buoys and tide gauges, have significant limitations, namely high costs [58]. On the contrary, solutions that enable sailors to collect and share meteorological data through electronic equipment installed on vessels are gaining prominence. This capability is crucial for aiding early decision-making while navigating maritime routes [57; 58; 59]. Consequently, it is imperative to comprehend the main technologies available for accessing such data that can help navigators to anticipate their sailing maneuvers towards safe navigation.