Recreational Sailing Fleets as a Coastal Observing System: A Citizen-Science Architecture and Metrological Methodology

Abstract

Coastal seas are the best-observed part of the ocean and still under-sampled relative to their variability. Thousands of recreational and charter sailing vessels traverse these waters annually, measuring wind, depth and water temperature with on-board instruments. These measurements are never collected, recorded or aggregated. We present Project SeaSense: a tiered, low-cost architecture that turns such vessels into a crowd-sourced mobile coastal observing system together with a metrological methodology for processing this raw, uncalibrated data. SeaSense offers a complementary data collection effort to institutional monitoring, by harvesting a vessel's existing marine-bus instruments for data and augmenting that with onboard surface-pressure and motion measurements; an optional flow-through module adds water quality. We describe the concept of operations, analyse the dominant residual error per parameter and rank how much usable signal each channel should yield, and report on a 69-day endurance deployment. Surface pressure meets synoptic targets after a single scalar correction, harvested depth is usable in shallow water, and the two tiers correct each other; wet-chemistry channels met their sensitivity requirements but not their endurance. The contribution is the observing-system concept, its methodology, and a first per-parameter answer to how much signal opportunistic fleet data can yield.

© 2026 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses. Accepted manuscript.