The company operates the 300-passenger ro-pax Baldur and the 150-passenger Saerun in Breidafjordur.
It added the bigger ship last year.
Seatours' revenue in 2014 was ISK 560m ($4.23m).
Eimskip did not reveal a price for the deal, but said: "Eimskip is taking steps in further strengthening its sea-related tourist services, but the company has in recent years operated the ferry Herjolfur on a time charter for the Icelandic Road and Coastal Administration (IRCA)."
CEO
