Published: May 03, 2010 6:45 PM EDT

NORTH FORT MYERS. Fla - The search for a missing 55-year old man resumed again at 9:00 a.m. this morning.  On Sunday, divers responding to a dock located at 16050 Bay Pointe Boulevard after reports of a man drowning.

Lee Deputies say two brothers were boating when one of the men decided to jump into the water to cool off.  The man began to have difficulty swimming in the water. The other man jumped in to help him, but their boat began to float away. 

Several agencies were called out and search teams combed the waters off  the Caloosahatchee River until dive crews were unable to see due to the murky water.  

Investigators say the rescue operation has since turned into a recovery operation, as they believe there is little chance he'll be found alive.