  Small lightweight wave buoys, SFYs, designed to operate near the coast, have
been developed. The buoys are designed to record and transmit the full time
series of surface acceleration at $52$ Hz. The buoy uses the cellular network
to transfer data and position (up to $80$ km from the base station). This
reduces costs and increases band-width. The low cost and low weight permits the
buoys to be deployed easily, and in arrays in areas where satellite and wave
models struggle to resolve wave and current interaction. The buoys are tested
in a wave-flume, the open water and in the breaking waves of the surf. The
conditions range from calm to significant wave heights exceeding $7$ m and
crashing breakers with accelerations exceeding $10$ g. The high sample rate
captures the impulse of breaking waves, and allows them to be studied in
detail. Breaking waves are measured and quantified in the open water. We
measure breaking waves in the surf and recover the trajectory of waves breaking
in the field to a higher degree than previously done. The time series of
surface elevation, and accurate positioning, permits the signal of adjacent
buoys to be correlated in a coherent phase-resolved way. Finally, we offer an
explanation and solution for the ubiquitous low-frequency noise in IMU-based
buoys and discuss necessary sampling and design to measure in areas of breaking
waves.
