https://www.pcgamer.com/subnautica-celebrates-world-oceans-day-with-a-weekend-sale/

In celebration of World Oceans Day, Subnautica is on sale now through Monday, June 11 at 6pm BST / 10am PST. 

The deep sea survival game's weekend Steam sale lops 20 percent off its regular price—now £15.59/$19.99—with 15 percent of net developer profits going to sea life charity Whale and Dolphin Conservation.