You can make some adjustments in a kayak. The most important adjustment is to adjust the footrest and the rudder. Please watch the video to find out how to make this adjustment.
You can adjust both the seat and the footrests on a kayak.The footrests are easily adjusted by sliding them back and forth in the cockpit until they are reasonably far from the seat.
To adjust the seat you often need tools, and this is something you might do if you own a kayak, but not normally something you would do with a rental kayak, as it takes quite a bit of time.
How to sit in the kayak
Sit straight or lean slightly forward with your upper body. Your legs should be slightly bent so that your knees should have contact with the inside shell of thekayak. Your feet should have support against the pedals / footrests. The sitting position determines how good a balance you get in the kayak and how well you can control it. If you sit well, it is you who decides how you want the kayak to move.