Building sandcastles in a satin gown. Boogie boarding in a tuxedo. Sunbathing in a top hat. Confused? If so, you can probably relate to the unsuspecting Coney Island beachgoers who witnessed this year’s Black Tie Beach Day.

Improv Everywhere coordinated the snazzy sand ‘n’ surf soirée. Hundreds of participants dressed up fairytale ball-style and hit the beach for a sunny Saturday afternoon filled with typical seaside activities.

The professional pranksters pulled off the stunt last month and just released a YouTube video of the shenanigans that show the hilariously confused reactions at the event.

BONUS: Exclusive Photographs of Black Tie Beach Day

Black Tie Beach Day

1. 
   

   1. Bow Tie and Beach Towel

2. 
   

   2. “What’s this guy’s deal, Mommy?”

3. 
   

   3. Cheers, Darling

4. 
   

   4. Prom 1998 — Wooo!

5. 
   

   5. Tails in the Surf

6. 
   

   6. Nap Sand Fort

7. 
   

   7. Contemplative

8. 
   

   8. Taking a Stroll

9. 
   

   9. Frolic

10. 
    

    10. Swimmies for Safety First

11. 
    

    11. Sand Strut

12. 
    

    12. Confused Beachgoer

13. 
    

    13. Making a Splash

14. 
    

    14. Hmmm

15. 
    

    15. Hugs?

16. 
    

    16. Also Formal Robot Day?

17. 
    

    17. Frisbee Time

Read more: http://mashable.com/2012/09/10/improv-everywhere-black-tie-beach-day-2012/