Wildlife workers have returned to the Everglades National Park in Florida to try leading 41 pilot whales out of dangerously shallow waters and back to the ocean.
The whales were spotted on Tuesday in a remote area on the western boundary of the park and about 20 miles east of where they normally live.
It takes more than an hour to reach the spot from the nearest boat ramp and there is no mobile phone service, complicating rescue efforts.
Of the 51 whales that ended up in the Everglades, six were found dead, and four had to be put down.
Workers from the National Park Service and the National Oceanic and Atmospheric Administration spent Wednesday trying to herd the whales towards the ocean, but the marine mammals were not co-operating.