A VMCM S4 current meter intercomparison on a surface mooring in shallow water

An intercomparison between the EG&G Vector Measuring Current Meter and the InterOcean S4 current meter was conducted in a shallow-water surface wave environment in Buzzards Bay, MA from 15 May to 1 July, 1985. A preliminary analysis of the S4 and VMCM current data indicates that the S4 on average over-responds in comparison to the VMCM, but a simple model of the known under-response of the VMCM in oscillatory flows suggests that the absolute accuracy of the S4 hourly averaged velocities may be quite good in the wave and mooring-motion conditions which existed during the field experiment. Typical speed differences were less than 10% and direction differences were generally less than 10 degrees.