aerodynamics (anti)

[lessthanjakejohn]

I'm doing a water rocket experiment type thing at my school and we launch 2 liter bottles with water and air up and shoot for the most possible hangtime. At the apogee of the flight a capsule comes off with a parachute. I am wanting to know if any of you know what would be the best shape for the most drag, (like an anti tear drop) so the parashute will take a long ime to get down there is also a limit to the diameter of the capsule and it is the diameter of the 2 lt bottle. The length limit of the parashute is 2 meters with a maximum area of 400 cms for the parachute well thanks, yea that sounded a bit weird