Hydromancy - a form of prophecy (Divination)* aided by observation of water.
*Divination (from Latin divinare, 'to foresee, to foretell, to predict, to prophesy')[2] is the attempt to gain insight into a question or situation by way of an occultic, standardized process or ritual.[3] Used in various forms throughout history, diviners ascertain their interpretations of how a querent should proceed by reading signs, events, or omens, or through alleged contact with a supernatural agency.[4]" e.g. by observing the state of the water before deciding sail size to use looking for omens in the random typing of the Weather Cat. Seems like a perfect fit.
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What happens in a black hole stays in a black hole.