Michael Nohrenberg, 54, of Chalmette, La., and his granddaughter, Kalie, 11, of Houston, were reported in relatively good condition after spending the night under a piece of tarp in Bayou Bienvenue, The Times-Picayune newspaper in New Orleans reports.

Nohrenberg told authorities he intended to give his granddaughter a ride on his jet ski when it apparently was stuck in the mud. The pair waded to the base of a transmission tower about a quarter of a mile from the boat launch for safety, Nohrenberg told The Times-Picayune.

The U.S. Coast Guard along with the St. Bernard Sheriff's Office and the Louisiana Department of Wildlife and Fisheries began search for the two Sunday evening after family members reported them missing.