At the end of the Anglo-Cherokee War, in 1761, Sumter was invited to join what was to become known as the "Timberlake Expedition," organized by Colonel Adam Stephen and led by Henry Timberlake (who had volunteered for the assignment) [REF].
At one point early in the nearly year and a half long journey, an entry in Timberlake's journal describes Sumter's swimming nearly a half-mile in the icy waters to retrieve their canoe, which had drifted away while they were exploring a cave [REF].