Ahti was the old Finnish god of the sea, who used to reside in the Baltic Sea.
He was married to married goddess Vellamo, with both of them residing at bottom of sea which is called Ahtola, and resides over lesser creatures of the sea, such as Väki and the Iku-Turso. The old pagans of Finland prayed to Ahti for generous catch of fish and good weathers at sea.
He was partially impetuoius and vindictive towards his people, though he was just and loving king to own folk.
Some old witches also used the name of sea god in their incantations and spells.