Water standard
The water standard, or water-backed representative money, is the standard type of currency used by the interplanetary nations of the Solar System following the proliferation of spaceborne colonies and the increase of space industrial capacity. It is informally referred to as hydrocurrency. The value of water is pronounced due to the vast distances of space and the challenge of interplanetary trade. Water-rich bodies like Plateia (where the bulk of the power of the interplanetary polities such as the Coalition, Commonwealth, and Union State is held) and Danavus are in a powerful position, as they essentially control the supply of water and influence the economies of other planets and moons within their proximity. On Plateia, the effect of the water standard is less pronounced as a result of the large native hydrosphere. Beyond its surface,however, these currencies exist as a governmental promise to be redeemed for water at a fixed rate. With the growth of space colonies that do not have an immediate access to water, these nations maintain significant reserves on both Plateia and foreign worlds, with some even located in certain sectors of space.
In the early days of colonization and interplanetary trade, the water-rich nations of Plateia naturally exported their liquid water and foodstocks in exchange for imports of minerals and rare metals, as there was little in the way of agricultural or hydrological colonial infrastructure. As colonial ventures progressed and the non-Plateian born human population began to rise, however, water began to gradually be used as a standard of value—similar to how gold was used as a standard in the past on Plateia. A fixed amount of water became the basis for the value of goods and services, not only between colonies and their Plateian overlords, but also between different colonies. This system has been implicitly maintained by the Plateian nations as a result of their natural benefit from the water standard, levying their massive water reserves to maintain economic superiority. The relative scarcity of water in different areas of the Solar System, however, has led to the growth of power imbalances in independent polities, the rise of black markets and crime relating to illegal water hoarding and trading, in addition to offering another facet of piracy.
As water becomes a particularly scarce and precious resource due to the continued growth of humanity beyond Plateia—and the planet's very own geopolitical instabilities—conflicts are very well possible in regards to access to water-rich bodies and the control of water reserves. In addition, the price of water as a commodity is subject to speculation and market manipulation wherever possible, leading to further potential economic crises on the horizon as the Plateian nations wage war amongst themselves.