A boat matching the description of a vessel responsible for a fatal hit-and-run that killed a teenager waterskiing in the Miami area over the weekend is now in custody, RadarOnline.com has learned. The boat’s owner is cooperating with the investigation, according to an update from a spokesperson for the Florida Fish and Wildlife Conservation Commission. It’s unclear if that person was the individual behind the wheel when the boat struck 15-year-old Ella Adler at Nixon Beach in Key Biscayne before quickly fleeing the scene of the tragedy. Eyewitnesses described the vessel as a center console bo…