ST. PETERSBURG — Ann Steward and her boyfriend Michael Rossi thought they’d found their dream boat. The young couple recently saw a Craigslist ad for what they thought was a good deal on a used, 24-foot cabin motorboat. They picked it up Monday from a Tampa pawnshop. Just before 1 p.m. Tuesday, less than 24 hours after the purchase, the couple and their three young children were stranded in Tampa Bay, about 20 to 30 yards south of the center span of the Gandy Bridge, after a fire started in the engine compartment.”We wanted to take it on a trial run,” said Steward, 24. “But about a mile or two into the trip the boat started smoking and smelling really bad.”Rossi dropped the anchor, but winds kept pushing the boat closer to the bridge.Someone driving by saw the smoke and called 911.Within minutes, a crew from the Florida Fish and Wildlife Conservation Commission, which has an office nearby, reached the boat.”If that boat hit pylons it would all be over,” said FWC Officer Robert Scholl. “It was crucial that we get there.”FWC officers loaded Steward and the kids onto their boat and helped Rossi put out the blaze with a fire extinguisher he had on board. He opted to stay with the vessel until it could be towed to shore.Steward said she and Rossi had been saving up and looking for a boat for a while. She grew up with a boat and wanted her kids to have that experience as well.On Tuesday, though, she was just glad to be on land. She watched as her children, girls ages 7 and 5, and a 1-year-old boy, played under a tree. “I was really scared, being out in the water like that,” Steward said as she waited for her husband and their boat to be towed back to shore. “I’m so happy help showed up.”Officials are still investigating the cause of the fire.