Validation of wave sensors on navigational buoys

The MOTUS directional wave sensor is a newly developed sensor based on MEMS technology (micro-electro-mechanical system) to be mounted on hosting buoys, like typical navigational buoys used worldwide or other buoys dedicated for metocean data collection. Two of these sensors were deployed off Karmøy (western Norway) at 200 m depth for a test period of 2 years on two buoys, a Tideland SB138P and an EMM2.0 Coastal monitoring buoy. A directional Datawell Waverider was used as reference. All three buoys were deployed within 500 to 800 m apart. Currents and wind measurements were sampled simultaneously. Also assessed are effects of different moorings, additional weights on the buoys and comparison of directions when mounting an additional compass to correct for magnetic errors. Wave measurements (Hs, spectral distribution and wave directions) measured by the MOTUS on the two buoys are validated against Waverider data using the WaveEval Tool developed in the Coastal Data Information Program (CDIP).