WP-DC16 or WP-DC6

I currently have a Canon A710IS with a cracked LCD. I was about to purchase an A720IS and get the WP-DC16 underwater housing for it, does anyone know if it will fit the 710IS as well or is that limited to just the DC6. I only ask as my wife wants me to use the one with the cracked LCD on a dive or two to prove it won't leak on the new camera.