Navigation in Space (part 4)

There's a reason things are done in Star Trek the way they are. I've spent some time, myself, as a helmsman aboard the Enterprise in the VR game, Star Trek: Bridge Crew, and it made me question starship navigational tropes. Why do we focus so much on X and Y coordinates (360 degrees left to right) and very little on Z (height and depth?) It's a paradigm we are accustomed to, because we've grown up in a world with sea level as the median, the upper atmosphere as our ceiling, and the ocean floor as our maximum depth. In the Star Trek game, it's not much different, and though you can theoretically fly any direction, starship engagements basically remain in a 2-dimensional flat plane. Sure, you can raise and lower your depth some, but for the most part, you are fighting along the X and Y axis, ignoring the Z most of the time. Yet as some of you know in the famous “Star Trek: The Wrath of Khan” movie, Captain Kirk outsmarts his X/Y-thinking enemy using the Z axis to his advantage. This is why I turned to my Navy friend, who explained to me how directions are conducted underwater in submarine maneuvers. In a submarine, directions would be given like this: “Helm, come to course 270. Diving Officer, make your depth 200, 10 degree down angle.” If an enemy sub was sighted: “Contact S-9 is bearing 090 with a 0-degree angle on the bow,” which means another vessel that is 90-degrees to the right and is heading directly at you. Using the 360 degree XY circle for directions and establishing an angle for depth or height on the Z axis (though without the sea level reference point) are definitely useful navigational directions for a starship pilot.