In short, water's a hard trick for game programmers because a game with realistic above water, surface, and underwater play would need to have two or even three physics engines stacked on top of one another, each with its own laws. And given that water's often considered a tertiary feature at best, there hasn't been much development money invested in physics engines to handle water's unique environment. Developers tend to treat swimming as flying, but slower. In reality being underwater is a full-sensory experience that affords you 360 degrees of movement and makes you feel the ocean's energy in a way you never feel air -- and that's almost impossible to translate in a medium as physically detached as videogames. And it isn't just about waves, either. Developers are currently unable to create currents and rip currents, simulate undertow, have water react to shore conditions, support much aquatic life or even show the tidal cycle. Unlike the living system that supports our planet, video game oceans seem like dead space.
But water presents huge gameplay possibilities, and there are steps developers can take to deliver better underwater gameplay. Hydrophobia may have landed hard, but the HydroEngine managed to create fluid dynamics that were far more convincing than most games. (HydroEngine is probably for sale in Dark Energy Digital's bankruptcy proceedings and it works with the Havok Engine, HINT HINT.) While GTA V's breaking waves amounted to a visual trick, they remained convincing at a distance. And the aforementioned indie game Infinite SCUBA contains the most faithful buoyancy physics and equipment I've seen so far. Assassin's Creed 4's diving sections, by contrast, fell prey to many of the old problems with video game swimming, but the currents that sucked Edward through underwater tunnels got closer to that tactile sense of fluid dynamics than any other game I've played.
But for a smart designer who's willing to get creative, water opens a whole new medium to play with. Water levels usually serve to obscure hidden items or as breath-hold obstacle courses, but they could be so much more. Underwater action scenes ala Thunderball could be a huge customer draw if done right (and by "if done right" I mean "without the restrictive linearity Call of Duty: Ghosts employed"). Indeed, underwater action scenes could feel tactical and visceral if studios paid more attention to the technical aspects of diving. Imagine a game where your air is running out, and you have to ambush other divers and steal their tanks to survive -- that I would play. If we could marry the impressive visuals in Call of Duty: Ghosts's SCUBA sections with the frantic moment in Far Cry 3 where the player had to escape a ship by snagging air tanks floating in the wreckage, we'd be most of the way there.
Underwater settings also have unrealized potential as an exploration environment. There is some movement in this direction - Infinite SCUBA allows the player to dive a WWII wreck, find artifacts and identify coral and fish species - and Abzu looks like it will take this direction as well. Endless Ocean and its sequel promised this, but failed to make it engaging enough for wide appeal. But as one of the great unexplored environments on earth, the ocean provides a perfect setting for finding lost things or unknown creatures. And if a developers got creative, a game that tackled the ocean as its primary environment could do amazing things in this vein - picture an exploration/horror game set in the deep sea.
Apart from the vast potential in the setting, there's another reason developers should pay attention to our watery world. To be frank, the ocean is the world's circulatory system, mankind's largest transportation grid for goods, humanity's refrigerator and - increasingly - our trash dump. It also produces the majority of our oxygen. If you see some conflict in those purposes, you're not the only one. As global warming threatens important ocean characteristics like temperature, salinity and thermohaline circulation, scientists are expressing concern about ocean health. But the fact is that though the ocean affects everyone on Earth, very few people will regularly connect with the ocean as an environment - and fewer will spend more than a few hours in their lifetime beneath the surface. For most people, the ocean is out of sight, out of mind.
But games can place us in an unfamiliar setting and convey its reality. They have the potential to let people who live thousands of miles from the ocean engage with underwater environments and make them tangible. Even if that engagement isn't focused on environmentalism, introducing the ocean as a living thing -- not a dead zone -- could bring players closer to understanding its importance.
Developers are doing the best they can to convey the physics of water, but significant technical barriers remain. However, for an enterprising developer who's willing to throw their weight behind creating great environments, the sea offers a fitting playground for adventure, education and human curiosity.