Don't worry ! Enjoy the beach !! remember, even if you do eat a little more than you want, that doesn't make you a bad person or an unhealthy one.
One less than perfect weekend or one over indulgent meal WILL NOT make or break your healthy lifestyle. If you eat right five out of seven days this week, you're still doing better than the average American.
Try to be mindful of your portions, but if you over indulge, that's not the end of the world. You'll just eat a little better when you return. This is a lifestyle change, not a diet.