The 1.12 and the 1.11 have nearly identical drag profiles but obtained in different ways. We know the 1.11 is rocket fast for straight line courses such as 2k's. River courses and Head Races can require more turning, so the 1.12's shorter waterline and more rockered shape allows the 1.12 to turn more easily while giving the athlete a more "dynamic" feel and essentially more feedback.
The 1.12 is slightly wider at the waterline (5mm), draws additional depth (1 cm more than the 1.11). The 1.12 is also shorter than the 1.11 with the 1.12 having a waterline length of 6.94 meters (7.34 for the 1.11).