The increase in shipping activity and nautical tourism in our seas has dire implications on the health of marine fauna. Procedures for measuring underwater radiated noise (URN) of vessels have been introduced (e.g., ANSI/ASA S12.64-2009 and ISO 17208-2:2019 standards), and various database of shipping URN have been collected. However, these are designed for cooperating vessels in controlled areas, and for vessels including automatic identification systems (AIS). As such, not a lot of data is available for the URN of unidentified vessels of opportunity (VOO), especially for small vessels that do not carry AIS. To this end, we assembled a dictionary for VOO’s URN from acoustic and visual recordings made within Šibenik canal in Croatia. The dictionary comprises source pressure levels in 1/3 octave bandwidth at the closest point of approach (CPA), picture and video of the vessel, and the vessel’s speed, size and type. The database is open access and includes 1283 vessels, recorded during a period of 26 days. Approximately 20 types of vessels were recorded, including various types of ferries, fishing boats, yachts, and small speed boats. To the best of our knowledge, this is one of the largest databases of vessel URN in general and the most extensive database for small coastal vessels. In this paper, we share the structure of our database, the analysis methodology, and the details of the openly shared tool we created for comparing shipping URN.