This rocket is still in experimentation. 
Originally the white heavy golf ball was on the nose (where the light yellow is now) 
Attached to the body and the parachute through the hole in the nose with 1 m of string. 
The Idea was that when the rocket falls after apogee the ball would fall first , 
yank the cord and deploy the parachute. 
I just forgot about the air braking effect just after all the water is gone. 
Result..The parachute deployed at about only 12 or 15 m real hard. 
On the  third attempt the golf ball shot through real fast ! and disappeared. from view..:-( 
There was some panic on the ground....:;-> 
 
The parachute is very simple and effective. 
Made of plastic garbage bag cut  1/3 from the bottom of the bag,   
Strenghtened and attached to strings at 4 points with clear tape .. 
The folding is critical and should loosely be done in an accordion fashion. 
like that __>   WWW 
I'm still working on a simple solution to open the chute at apogee.