The dead men were identified as pilot Charles Knight, 38, of Mount Airy, Md., and passenger Matt Clark, 36, of Pasadena, Md.
Wreckage of the helicopter was found about 6 p.m. "in about 55 feet of water," Capt. Brian Albert of the Maryland Natural Resources Police said in a statement, ABC News reported.
The U.S. Coast Guard said it received a call about the crash about 12:30 p.m. and began searching for the aircraft, FOX 5 of Washington, D.C., reported.
Authorities told FOX 5 that the Guinbal Cabri G2GL helicopter had taken off from Tipton Airport near Fort Meade and crashed southeast of Bloody Point, about 1 mile south of Kent Island.
County Emergency Services Department Assistant Chief Scott Wheatley said debris from the wreck dotted the water.
Trevor Hardman was fishing for rockfish with his 15-year-old son and his friend when he heard another boater report the crash over marine VHF radio. When he arrived at the site about a mile away, "there was nothing but pieces everywhere and jet fuel," Hardman, a Prince George's County firefighter, told the Baltimore Sun.
Hardman said he pulled a bag out of the water that contained a flight log and a maintenance record for the Cabri G2 helicopter, made by the French company Guimbal. He said he gave the records to the U.S. Coast Guard.
The Associated Press contributed to this story.