The beauty of Endless Ocean is that players can do as much or as little as they like. The relaxed and calm atmosphere of the game gives divers the freedom to explore special locations such as shipwrecks and underwater ruins, discover and interact with sea-life, complete fish logs or simply relax in the soothing environment.
The game opens with players onboard a diving boat, with a crew member who provides advice and tips on finding the best locations for fish and helps players advance the storyline. Players must assume the role of the diver, opting to go into the water to explore sea-life at their own pace utilising tools such as a camera or fish bait. In the cabin on the boat, divers can access the fish log to check out the fish that have been spotted, as well as carry out missions like photographing marine life. These missions unlock content, such as new items to use underwater, or different diving gear that can be used to customize the diver.