Open Sea
The coastal waters around Scotland, which extend to depths of around 30 metres, give way to the open sea areas of the continental shelf, with waters of up to about 200 metres in depth, and beyond. The open sea to the east of Scotland is relatively shallow continental shelf water, in comparison to the deep sea of the Rockall Trough with depths in excess of 1,000 metres found relatively close to the coast off the west and north of mainland Scotland.
The water masses of the open sea are moved by winds and tides, and provide a natural habitat for a diverse range of species - from phytoplankton (microscopic aquatic plants) found in the upper layers of the sea, to fish and larger cetaceans (the whales) located in the deep sea.