Tommy Howze was fishing the west Pascagoula River on Friday when he saw an eye looking up at him from the water.
At first he thought it might be a nutria rat, a type of large rodent that lives in the marshes of the area. But when it moved, he saw the size of the animal.
It was a big manatee, eight to 10 feet long.
He has posted several videos on Facebook.
"It was pretty incredible looking," Howze told the Sun Herald. "They are so big."
Manatees, sometimes called sea cows, can grow to 13 feet long and 1,300 pounds. They live in slow rivers, canals, saltwater bays, estuaries and coastal areas and they are migratory. All three species of manatee are considered endangered.
Howze said he saw one on Friday, five the day before and two earlier in the week in an area of the river that forms a lake.
He said there were more on Thursday in the main river.
He's seeing them in what is called the west branch of the Pascagoula River that runs by Gautier. He has been spotting them just north of the long Interstate 10 bridge in the west river.
Howze said he just bought a house on the river last month and has been enjoying fishing.
The manatees surprised him, he said, but they didn't scare him.
"I didn't feel threatened by it at all," he said.