How do i convince my parents to let me go to the beach with a friend?

My friend invited me to go with her to the beach with her mom, granny, and two other sisters. we live in Kentucky and we are going to Florida, we would fly. My mom already said it was fine because she is friends with my her parents. My dad is being very protective though and he is afraid we are going to run off and do something stupid or bad, or i might get abducted or something like that! How can i convince him to let me go?