Before the Gates
The history of water magic prior to the gates is... complicated. The Hysilens seldom mention the use of water magic in the ruins present of their society, but they were believed to have used it in... inventive ways to pull water-laden asteroids around systems to create orbital habitats and the like.
It's believed that, as a result, they primarily used it for utilitarian purposes; the magic seemed to have little value in space for the Hysilens, but on planets it was a different matter, with significant evidence of major, magical water-based changes to planets as the Hysilens expanded, though nobody knows for what ends.
Early History
Unlike most forms of magic, the
Shard Ritual didn't actually change much for water magic, as it found purchase across the sector in the early days of spaceflight all the same; its uses in orbital agriculture made it nearly mandatory in the early days, as did its general ability to manipulate water and ice - it was fairly common for
Hydromancers to be used to capture ice asteroids for extraction in the early days, prior to the significant technological advancements of the cluster.
Modern History
Nowadays, water magic has receded a bit from modern memory, with only a few powers - such as the Argon Federation - making active use of it doctrinally. That's not to say it isn't very valuable all the same, but the invention of more efficient technological solutions to orbital agriculture and water production that doesn't rely on ice asteroids or
Aether has greatly diminished the perceived value of water casters.
Some nations - such as the Federation - still make great use of water magic in nonstandard ways, however, with the Federation infamously using it during the Argon Crisis to effectively punch holes in ships and vent their atmosphere, a rather controversial tactic still utilised by the Argon today.
Aldrin History
In contrast to the cluster at large, water magic in Aldrin retains an incredibly prevalent degree of relevance societally; with so much water on the planet, its abilities are extremely valuable, and the ability to manipulate ice is very handy, as well. Generally speaking, most Aldriners consider water magic to be among the most important types of basic magic.