i can help you, but since its a long time i haven't watched aquamarine, is it possible if you can give a video link the part when she dances because i dont quite remember. Since i dont remember much, i'll give you the soundtrack list of the songs played in the movie.

Soundtrack List:
Cheyenne Kimball – "One Original Thing"
Nikki Flores – "Strike"
Sara Paxton – "Connected"
Teddy Geiger – "Gentleman"
Teitur – "One and Only"
Atomic Kitten – "Right Now"
Emma Roberts – "Island in the Sun"
Jonas Brothers – "Time For Me To Fly"
Courtney Jaye – "Can't Behave"
Nikki Cleary – "Summertime Guys"
Mandy Moore – "One Way or Another"
Stellastarr – "Sweet Troubled Soul"
Bodyrockers – "I Like the Way You Move"

Oh thank you my dear i got a very biiiiig help froem you,the song i was looking for is island in the sun!Thanx a million times

You're Welcome^^^

island in the sun and your welcome