Robyn,
I would say for an 11 and 13 year old, I'd need to know if they are boys, girls or one of each... in general, I'd say these are things they "must see and do"...
1. GO TO THE BEACH!! SWIM IN THE OCEAN!!
2. Go to the Pier, eat Thasher's French Fries and play all the games and ride the rides.
3. Go to Bahia Marina, OC Fishing Center or Talbot Street Marina to see the fishing boats head in with the day's catch
http://www.bahiamarina.com/Â
http://www.ocfishing.com/Â
http://www.talbotstreetmarina.com/ 4. Head to the fishing part of the pier and have them fish!Â
http://ocfishingpier.com/Â
5. Go to the Ocean City Life-Saving Station Museum and take in the exhibits
http://www.ocmuseum.org/Â
6. GO TO THE BEACH!!! SWIM IN THE OCEAN!!!!
7. While on the beach and swimming in the ocean, have a telescope picture taken... they are the best souvenir!Â
http://www.ocbeachphotos.com/ 8. Take a morning bike ride on the boardwalk.....
http://www.atlanticbreezes.com/oceancitybicycles.htm 9. Just go walk and explore the boardwalkÂ
http://ocboards.com/map.phpÂ
That's just some ideas... make sure you pick up a Sunny Day Guide in your hotel/motel lobby to find other great things to do and loads of money saving coupons..... also, for lots of other ideas, head to the Visitor's Center at the Convention Center on 40th Street.
Have Fun!