What determines how loose a surfboard feels?

[jetboy]

Err everything!
Volume
Length
Width
Outline
Weight
Rails
Tail design
Rocker
Bottom shape
Fin setup
Fin size
Construction and weight
Also looseness can be interpreted differently. For some it's a skatey board that breaks the fins to slide easily. For others it's an alive board that is super responsive quickly. For me it's a combination of both those plus a board that the tail does not bog down and is easily thrown high in moves.