Nintendo has announced that Splatoon will be updated with its third free additional map and eighth map overall tomorrow morning (Saturday 20 June). Bluefin Depot will release worldwide as part of a free update.
Bluefin Depot joins Port Mackerel and Kelp Dome, which have been added to the game since it was released in late May. They form part of a string of free new content being added to the Wii U multiplayer online shooter over the course of the summer.
— Nintendo UK (@NintendoUK) June 19, 2015
The map can already be found in the game's single player mode in the Octo Valley part of the game's hub world Inkopolis. Variations of it can be Bluefin Depot can be seen on stages 15 and 20.
Further updates are expected in the coming months ahead of a major update in August which will add four-person online teams to the standard Turf War game mode, custom battles which can take place on any map with any rules and new weapons and gear.
Another map, called Camp Triggerfish has been spotted and is expected to be released in the coming weeks.
Splatoon has been a big success for Nintendo, receiving great reviews and selling strongly for a Wii U title. You can read our review of the Nintendo's new IP here.