Rolling well will require you to get low on the front deck of your kayak. The ability to get low depends to a large extent upon how flexible your hamstrings are. I pay considerable attention to stretching my hamstrings each week. A couple of weeks ago I was talking to Bill the owner of Lumpy Paddles and we were discussing the effect of masik height (deck beam near your thighs). We were discussing the impact that moving your legs can have on your ability to roll. There is a school of thought that suggests the lowest tightest masik you can get is the best for rolling. I beg to differ. If you are not highly flexible then a low masik will actually prevent you from getting low on the deck. Let me explain myself using two images.
Please excuse my hairy legs, they are not required for rolling. Note the obvious lower position I am able to get into by raising my knees and parting them slightly. The ultra low masik kayaks tend to cause my to assume the first position, whereas kayaks that allow a very slight rise and parting in my knees allow me to get much lower. This lowering of center of gravity helps my complete forward finishing rolls. It also helps me set up for lay-back rolls.The reason that this knee position helps appears to relate to the lengthening of the hamstrings when the legs bend as well as the changes in pelvis position when the legs angle outwards. It appears to me my pelvis tilts forwards more in this position.So next time you are wishing you could get lower for your forward finishing rolls consider what is happening to your knees and see if you can use your legs to help you get lower. Or ignore this advice and just keep stretching those hamstrings.