There is nothing as refreshing as a dip in the sea. And Goa offers some pristine and blue waters to swim in. Of course a lot of the beaches are rocky and with unsafe currents or no lifeguards. So best to stick to beaches that are manned by lifeguards like Candolim, Colva, Uttorda, Varca, Morjim, Ashvem and Mandrem. And also important to follow their guidelines with respect to the flags they put there to send the message whether it is safe or not to swim at a particular time.