Rivenese water

Rivenese water is almost exactly like ordinary water in appearance, save for the fact that it is slightly thicker and more gelatinous. It has however very special properties: when heated, the water "escapes" the source of the heat.

This effect is caused by the bacteria in the water. These bacteria are killed by heat, much the opposite as those found on Tahgira. In response to such temperature changes, the bacteria move away, carrying along parts of the water, and the surface tension of the water changes.

When ingested the bacteria would make a person sick. Because of this, the Rivenese people had a special powder to counter the bacteria's effects, and cooked in closed vessels.

This property was used by Gehn to make tunnels and "holes" through the water. The log carriage from Jungle Island to Book Assembly Island passed underwater, but through an 'air tunnel' created by heating rings. The pool of Jungle Island had some air holes in some points, which the submarine could use as stations. Ladders protruded from these holes.