It is my belief that the vast majority (possibly all) manufacturers have patently failed to provide adequate footrests for the majority of serious ocean kayaks. This problem is only accentuated where rudder systems are integrated into the kayak. What follows is a brief explanation of one potential solution. I am sure if you give it some thought you could develop superior versions which will meet the necessary requirements.
Footrests are very important in ensuring the development and maintenance of an efficient paddling stroke. They are also essential for the paddler to achieve an intimate connection and confidence in their kayak. Few things would frighten me more than going down a large wave with frail plastic footrests and/or a bulkhead which comprised only one or two layers of fibreglass mat. For when I stand my kayak vertically on its nose in surf (pirouette) I literally stand on my bulkhead, occasionally I have bottomed.
How would your footrests fare? Sure, not everybody wants to do this type of thing in their kayak. But some people are not given the choice: you have to land some time. Sitting tightly in a kayak gives the paddler a stronger empathy and security which a sloppy/spacious cockpit can never provide. I do not suggest that everyone should seek to cramp themselves into their kayak. I acknowledge that, when I first began kayaking, I really appreciated the space of a large cockpit. There are no absolutes, but I suggest that as you gain confidence, the provision of a snug fitting kayak will enhance and accelerate your kayaking ability. Its easier to surf, roll, brace and paddle long distances in a kayak which is fitted out well and adapted to your body.
So, having been influenced by John Wilde’s sailing feats (which require a kayak equipped with a rudder) and offered an irresistible price, I recently purchased a Greenlander II sea kayak (once again, my apologies Arunas). Previously I did not possess a kayak with a rudder. This was because I sought to construct an extremely strong (maybe excessively strong) bulkhead/footrest on my Pittarak which I did not wish to complicate with a rudder. Also rudders seem to be frail and vulnerable to damage in the surf (which I like: not the damage though Norm).
Having purchased the Greenlander I was faced with the obstacle of constructing a reliable bulkhead/footrest. Notably the existing forward bulkhead was set about 40cm beyond my feet: I’m about 6’1″. So after the arduous process of removing the existing bulkhead and reclaiming gallons of storage room I was determined to construct the bulkhead/footrest and rudder assembly aiming to create a configuration which allowed adjustment.
Because I am a selfish person I chose to make the bulkhead perfectly compatible with my size. No tall bastards can paddle it. However it would not be too difficult to make slight alterations to this design to accommodate taller people. Below is an illustration of my design, which I hope becomes self-evident. I have fixed a mast-step on the back of the bulkhead and also set a sheet of aluminium plate (about 3 x 100 x 120mm) into the back to stop the rudder-bar mount pulling the bolts, which fasten it to the bulkhead, through the fibreglass.
Just remember, it is much easier to make these adjustments before a kayak is built. Demand such features when you order your kayak, even if you are required to build or fashion some of the components yourself, it will pay off.