The animals were sighted off the Mississippi coastline on Saturday after being washed away from the Marine Life Aquarium in Gulfport.
Rescuers plan to train them to jump on to mats alongside their boats and take them to salt-water tanks to recover.
The bottlenose dolphins have lived most of their lives in captivity and cannot fend for themselves in the wild.
Moby Solangi, owner of the Marine Life Aquarium, said there was huge concern for the wellbeing of the animals.
She said: "Once we realised the dolphins had been swept out to sea during the hurricane, we feared that they had died.
US National Oceanic and Atmospheric Administration
"We are just thrilled that they have stayed together during the past couple of weeks."
Experts from the US National Oceanic and Atmospheric Administration Fisheries Service are helping with the rescue attempt.
NOAA Fisheries spokeswoman Connie Barclay said if the animals cannot be trained, they will have to be captured in nets.
"They'll surely die if we don't rescue them," she said.
Rescuers are waiting for salt-water tanks to be shipped in by the US Navy.
A wave estimated to be 40ft (12m) high swept the mammals from their tank at the aquarium and into the Mississippi Sound when Katrina struck on 29 August.