Low-Cost Pressure Gauges for Measuring Water Waves

Waves have profound effects on coastal geomorphology, but the understanding of wave climate effects on coastal ecology is limited due, in part, to the high cost of commercial wave gauges. High-cost gauges also limit the scope of coastal wave models and the ability of coastal land managers to design effective restoration, conservation and enhancement projects. To address these limitations, a low-cost do-it-yourself (DIY) wave gauge was constructed using commercial plumbing parts, a pressure sensor, an Arduino (R) microcontroller and adapted accessories. Details on gauge construction, coding and an instructional video tutorial are provided. Performance of the DIY gauge was determined by measuring the agreement of raw pressure data recorded by the DIY gauge to a comparable commercial gauge in both a laboratory wave channel study featuring a series of wave tests and in a complementary field test. Agreement of raw pressure data among gauges in the wave channel study was assessed using paired t-tests and by fitting linear models. Field test data agreement was assessed by comparing the total wave field energy recorded by each gauge and by fitting a linear model to recorded raw pressure data. Pressure data agreement between the gauges was excellent in all wave channel tests with mean differences between pressure readings consistently near zero and with 95% of all differences lying within +/- 63 Pascals (<1 cm static water depth), on average. The greatest variability between readings occurred within tests featuring high-frequency waves, mirroring results reported by others. Still, raw DIY wave gauge data explained, on average, 91% of the variance in raw commercial gauge data in wave channel tests. Field performance testing indicated similar gauge responses with 92% total wave energy agreement. Thus, the DIY wave gauge is a viable alternative to high-cost gauges that could improve the understanding and management of coastal environments.