A Lagrangian trajectory model, TRACMASS with the use of velocity fields calculated by the Rossby Centre (Swedish Hydrological and Meteorological Institute) circulation model, is employed to analyse trajectories of current-driven surface transport in the Gulf of Finland, the Baltic Sea, for the period of 1987-1991. Statistical analysis of trajectories is performed to calculate a map of probabilities for adverse impacts released in different sea areas to hit the coast. There is a clearly defined curve (equiprobability line) in the western part of the gulf from which the chances of the propagation of adverse impacts to either of the coasts are equal. The current-driven propagation of tracers from a wide area (of reduced risk) to the coast in the central and eastern parts of the gulf is unlikely within about three weeks. A safe fairway in terms of coastal protection goes over the equiprobability line and the area of reduced risk.

The properties of wave fields induced by high-speed ferries and recently introduced conventional ferries with increased cruise speeds are analysed for a site in Tallinn Bay, the Gulf of Finland, the Baltic Sea, located about 3 km from the sailing line and up to 8 km from the wave production area. The analysis is based on high-resolution profiling of the water surface for about 650 wakes from fast ferries, measured during 4 weeks in June-July 2008. The new large conventional ferries with cruise speeds of 25-30 knots (~45-55 km/h) sail at near-critical speeds along extensive sections of eastern Tallinn Bay, and excite wakes equivalent to those of high-speed ferries. The peak periods of these wakes are between 10 and 13 s. The typical daily highest ship wave is approximately 1.2 m, measured prior to wake breaking. The largest recorded ship wave in calm conditions had a height of 1.5 m and in the presence of some wind wave background 1.7 m. The cumulative impact of ship wakes results in a gradual increase in the suspended matter concentration in near-bottom water over the course of a day. The largest and longest ship waves produce considerable wave runup at the coast and prevent several coastal sections from achieving an equilibrium state. The largest ship waves have an asymmetric shape both in terms of the water surface elevation above and below the mean level and in terms of the shape of the wave front and back. The overall intensity of anthropogenic waves has remained at the same level as it was in the year 2002, although the ships that produced the highest waves in the past are no longer in service

Results of a detailed oceanographic survey in the Saint John River Estuary, New Brunswick, Canada are presented. It is shown that interfacial mixing occurs in this highly stratified basin at discrete locations at a particular phase of the tide leading to a plunging pycnocline at most of these locations. This process is possibly initiated by different kind of internal waves or/and the changing velocity direction on interaction with the irregular bathymetry. Analysis of the flow structure in terms of the critical Richardson number, based on previous studies in the Baltic Sea, shows that these mechanisms and similar phenomena evidently occur at strong density interfaces in the Baltic Sea area where internal waves are less regular but still essentially contribute to interfacial mixing.