For better readability of the table, pass into the landscape mode.
Latvia is part of the Baltic States in Northern Europe. Latvia shares land borders with Estonia to the north and Lithuania to the south — and both Russia and Belarus to the east. It is separated from Sweden by the Baltic Sea. Here's the map.
The Baltic Sea is one of the most recent and shallowest seas in the world. The deepest point (470m) is to the north of Gothland. The coastline of the territory of Latvia is 490 km long. Irbe channel links Riga Gulf with the central part of the Baltic Sea (between Kolka horn and Saaremaa island).
The Baltic Sea is a typical inland sea with about 250 inflowing rivers. Therefore, it has the least salty water in the world. Latvia also has another body of water, the Gulf of Riga, but unfortunately, the visibility does not tend to be good, just some 1-2 metres.
Lake diving is very popular in Latvia at the Sloka Lakes and Dridzis Lake which is Latvias deepest at 60 metres and both of these are used for diver certifications.