In this paper the hypothesis about Poissonian character of vessel traffic stream from Świnoujście to Szczecin has been verified. And the hypothesis about Non-Poissonian character of vessel traffic stream from Szczecin to Świnoujście has been verified. To reach this goal, VTS data from second half of 2009 has been used. To description of non- Poissonian vessel traffic stream, for the first time, mixed distributions have been use