21. Adelpha is broken up into several regions, which are hinted to be separated by large water masses . 22. The most important feature of this water mass is a section referred to as the sub-surface layer. 23. Offshore waters are divided into three-dimensional water masses , taking into account water properties, circulation patterns and energetics. 24. Once formed at a particular source, a water mass will travel some distance via large-scale ocean circulation. 25. Oceanic eddies are also usually made of water masses that are different from those outside of the eddy. 26. The total length of the coastline is 130 km while land water mass area stands at 308 km. 27. The deep-water masses are not capable of moving water at speeds comparable to that of wind-driven surface currents. 28. The final defined water mass in the Arctic Ocean is called Arctic Surface Water and is found from. 29. Another example is internal waves, which can be transmitted along the interface of two water masses of different densities. 30. Johnson, M . W . and E . Brinton . ( 1963 ) Biological species, water masses and currents.