Bermuda swimmer Lisa Blackburn has won a silver medal at the Caribbean Championships after smashing the national record in the 200 metre breastroke.The veteran swimmer swam a time of two minutes, 40.01 seconds in the Girl's 18 and Over final in Puerto Rico yesterday, breaking Jenny Smart's 1992 record.National coach Ben Smith said: “It was great to have (Lisa) swim that way in the final and will be a confidence boost for her as she continues her preparation for the Olympic qualification.”