This paper describes the results of more than 4,000 long-term (up to thousands of peak-wave periods) numerical simulations of nonlinear gravity surface waves performed for investigation of properties and estimation of statistics of extreme («freak») waves. The method of solution of 2-D potential wave’s equations based on conformal mapping is applied to the simulation of wave behavior assigned by different initial conditions, defined by JONSWAP and Pierson-Moskowitz spectra. It is shown that nonlinear wave evolution sometimes results in appearance of very big waves. There are no predictors for appearance of extreme waves, however, a height of dimensional waves is proportional to a significant wave height. The initial generation of extreme waves can occur simply as a result of group effects, but in some cases the largest wave suddenly starts to grow. It is followed sometimes by a strong concentration of wave energy around a peak vertical. It is taking place throughout several peak wave periods. It happens to an individual wave in a physical space, no energy exchange with surrounding waves taking place. Probability function for steep waves has been constructed. Such a function can be used for development of operational forecast of freak waves based on a standard forecast.

Descriptions and manifestations of tsunami-like events in Russian inland waters (lakes, rivers and water reservoirs) are collected and analyzed. For the time period of 400 years nine such events are found, whereof descriptions of seven events can be categorized as reliable. Data analysis confirms the possibility of tsunami wave generation in all types of inland waters. There is therefore a need to educate the general population about the risk of tsunami generation.

Regularities of seasonal variations of the Global Sea Level (GSL) based on satellite altimeter data for the years 1993-2008 are discussed. Two prediction models of GSL seasonal variations are offered: a deterministic model as the sum of the trend and GSL annual harmonic and an adaptive model of linear increase with additive seasonality. Considered are the results of testing and experiment forecasts of monthly averaged GSL values based on independent data for 2005-2008 period. It is shown that by 2013 GSL may increase 13-14 mm compared to the one in 2009.

The decision of global operative model of the White sea is compared to ship measurements, the satellite data and level fluctuations at hydrometeorological station "Solovki". The conclusion about satisfactory work of model becomes.

Representations about the mechanism of noise formation in the forward part of the underwater vehicle are considered and an attempt to consider elastic properties of the forward part of the case is accepted by use of model of a wedge. The conclusion about boundary layer thickness pulsations in a zone of laminarturbulent transition as to the most probable reason for the formation of turbulent noise in a forward part is done.