It's mid-April and on the Gulf of Bothnia between Sweden and Finland, the ice covering the sea is still a metre thick.
BBC(May 06, 2016)
The embayment just below it is the Gulf of Bothnia, part of the Baltic Sea.
Scientific American(Nov 22, 2011)
A chain of islands separates the southern part from the northern, or Gulf of Bothnia.
Various, The New Gresham Encyclopedia. Vol....(2010)