Guess what, boaters? A researcher at Florida Atlantic University says that motoring slowly through designated manatee protection habitats may put the meandering sea cows at greater risk of getting hacked up by your boat's motor. Says Dr. Edmund Gerstein, the university's director of marine mammal behavioral research: "In turbid waters where there is no visibility, slow speeds actually exacerbate the risks of collisions by making these boats inaudible to manatee