"Jump/ing on da rocks" means,
A. To start the act of drinking, or to work towards getting "crunk".
B. Means to actually jump on rocks, in a form of quick fluid movements over and up rock and/or rocky areas such as hillsides or rocky rivers.
C.When a female is
attracted to a male(you), in this case "da" is substituted with "my".
This is a less often used form,
the common form would be "balls" instead of "rocks".
Yo man tonight i gotta jump
on the rocks, because i really wanna get drunk.
Dude lets go to upper falls and jump on da rocks.
Dude
that chick was
jumping on my rocks.