Collecting acoustic data during vessel-based surveys can provide valuable insights into the acoustic ecology of marine animals and the potential impacts of noise. It is also challenging as vessel-based recording systems typically restrict maneuverability and are subject to loud vessel noise, while most remote recording systems are expensive and designed to be deployed for extended periods on moorings or autonomous vehicles. Here we present a low-cost, open-source, drifting recorder that offers a hand-deployable, accessible, and customizable option for collecting acoustic data for short periods from virtually any survey vessel. The system is based on an inexpensive electronics package (Raspberry Pi computer with sound card, GPS, satellite tracker and rechargeable battery) enclosed within a waterproof case fixed atop a custom spar buoy that measures approximately 1.4 m in height and weighs about 10 kg in air. The total material cost per unit is approximately $1000 USD, depending on the configuration, and all software and hardware will be made freely available for use and further development by other research groups. The system records audio using GPS-time, which allows for accurate synchronization with other data streams (e.g., vessel cameras, drone video, other recorders). In the summer of 2025, our research team deployed a prototype system 25 times during vessel-based surveys of North Atlantic right whales, amassing over 60 h of high-quality acoustic recordings. We are currently developing the capacity for these systems to transmit data in real-time and assessing the accuracy of sound source localization using an array of multiple recorders. We hope that this system will provide an open-source, customizable and accessible option for fine-scale acoustic monitoring of marine species and the ocean soundscape.