Hello,
Welcome to the board. From your description, I believe that this vase is designed by Vicke Lindstrand for Kosta, Sweden; is pattern number LG 131; and was designed in around 1955. The fishing nets should also have a string of polished roundals along their length - am I right?
Have a look and see if the mark/signature also includes the pattern number, that will confirm it

Cheers, Nigel