If you want to be really, really alone, head for 48°52.6’S 123°23.6’W in the South Pacific Ocean. That’s “Point Nemo,” the point in the ocean farthest from any land. You’ll be in the middle of 22,405,411 square kilometers of ocean, an area larger than the entire former Soviet Union.
The point on land farthest from any ocean is at 46°16.8’N 86°40.2’E, outside the Chinese city of Urumqi, in the Dzoosotoyn Elisen Desert. It’s 1,645 miles from the nearest coastline.