The coins found by Bartlett are part of the now-scattered treasure transported by the galleons, which have since broken up.
Bartlett said the crew used the boat propeller to blow a hole in the sandy ocean floor to reach bedrock eight feet (2.4 meters) down. The salvage operation lasted five days.
Like many Florida treasure hunters, Bartlett, a Pompano Beach kitchen and bathroom remodeler, dives as a hobby.
He said he did not hunt treasure for the money, and declined to say how much he would receive under contract with 1715 Fleet-Queens Jewels.
"I'm just a guy on a boat living the dream," Bartlett said.
Hunters like Bartlett typically work under contract with the company, which grants them a percentage of their find after the state of Florida exercises its right to 20 percent of the haul.
The company acquired legal custodianship of the sunken fleet from the heirs of world-renowned treasure hunter Mel Fisher.