Purpose. The purpose of the work is to assess the impact of the characteristics of modern conventional microelectromechanical inertial motion units on the errors in measuring the energy characteristics of surface waves by wave buoys.

Methods and Results. Several methods are considered for estimating the wave energy spectrum based on inertial measurements, including accelerometer/gyroscope/magnetometer data. Four algorithms for reconstructing vertical acceleration were analyzed for further assessment of the spectrum of sea surface elevations. Based on the data obtained in a field experiment from the MHI Stationary Oceanographic Platform, differences in estimates of wave heights using one or another algorithm are shown. The performed numerical experiment qualitatively reproduces the features of inertial measurements and their respective spectra observed in field conditions.

Conclusions. It has been shown that the accelerometer noise level of typical sensors is 3–4 orders of magnitude lower than the signal from surface waves, and the accuracy characteristics of such sensors provide measurement of wave heights with an error not exceeding the specification values, which is usually no more than 3%. The noise below the spectral peak frequency can be a serious problem in wave height estimation, as it hinders the reliable isolation of the spectral peak. A sufficient condition for the occurrence of such noise is nonlinearity in the "sea surface-sensor" system. The strongest low frequency noise is observed when using an algorithm based on the Kalman filter. Thus, for minimizing wave height measurement errors, the choice of an inertial data processing algorithm seems to be more significant than the choice of a specific sensor model.