noun - Sanity (from Latin: sānitās) refers to the soundness, rationality and healthiness of the human mind, as opposed to insanity. A person is sane if he is rational. In the world of open water swimming, this soundness of mind can be defined differently than what is defined by contemporary society for land-based activities. Sanity in the open water swimming community can refer to the mental state of mind of those open water swimmers who willingly attempt extreme swimming, ice swimming, marathon swimming, night swimming, and channel swimming through the night, and among marine life, waves, currents, and tidal flows.
His neighbors began to doubt his sanity, but marathon swimmers knew the 3-way crossing was within his capabilities.
Middle English sanite, from Anglo-French sanité, from Latin sanitat-, sanitas health, sanity, from sanus healthy, sane. First Known Use: 15th century