At long last, someone has addressed the urgent question of naval warfare in space! I am not joking when I say this. Check out this article. I am a fan of science fiction, especially naval science fiction such as the Honor Harrington series by David Weber. Most SF novels use a known historical analogue of water naval combat as the basis for how they depict space-based warfare. Typically, this involves super-humongous ships engaged in battle over thousands of kilometers behaving as if they were duking it out at some far future Trafalgar. This analogy is dubious, on the grounds that modern water naval combat is itself far removed from Nelson’s day, or even from the Jutland battle of 1916. Read about the Battle of Midway for just how different things were in the 1940’s! The American and Japanese fleets never sighted each other. Damage was inflicted, almost totally, by aircraft-delivered weapons.
The nature of space battles of the future can’t truly be predicted, because we don’t know what kinds of weaponry will exist or what it will do. My money is on missiles, because they can change direction to strike at targets after they have been fired. Presumably, a laser or plasma gun will only be able to fire in a single direction. If an enemy vessel is far enough away, it will likely evade. So direct fire weapons will probably only be useful at comparatively shorter ranges, unlike a missile.
The major trend of almost all weapons since the invention of gunpowder firearms several hundred years ago is for higher lethality at greater range. Even lower lethality at greater range is still a good bet because it allows the firer to stay outside the range of an opponent’s weapons. Therefore, I think that the longest range weapons that provide the best chance of hitting the target will be the primary weaponry deployed on a spacegoing warship. I don’t envision battleships like the Yamato (yeah, Starblazers!) or the Galactica. No Star Destroyers either. For that matter, I don’t foresee even the USS Enterprise. Instead, I think most space warships will be akin to missile boats or corvettes of some kind or another – fast, inexpensive, and relatively small.
For a much more near-future examination of the potential for war in space, more science fact than science fiction, read this Time magazine piece.