Hi Ole,
not sure that I have covered this before. The ORCA is not the fastest craft on the market out there... also it is not light at 15 kg and this along with the hull design contribute to its stability. What you will find is big swell is a lift from the rear as the bottom is relative wide and flat a bit like a spec ski, whilst the bow is tall and has high volume like most good skis. I am still amazed as to how stable and forgiving the craft is generally. In cross swell and when catching runs or downwind, you will find that the rear may have tendency to move a bit but in fact the craft is trying to align it self with the flow of the water steared by the general direct of the bow. So, play with the rudder to compensate based on which direction you want to go... this is heaps of fun. The idea here is that you need to TRUST your craft, and pay attention when it is giving you feedback as you have not have attacked a wave at the most efficient angle and the craft is attempting to self correct itself. Teh good thing is that instead of being thrown off, you may momentarily change direction and importantly stay upright!
Downwind, the way it catches runs is simply exilerating and you will know if you are doing it well by listening to the sound of the venturi (that's if there is no wind!).
At the last Bridge to Beach that I did about 2 years ago, there was 2m swell at the Heads, and I finished 69, which to me as a mid packer, was quite satisfying, I saw other paddlers in more sophisticated and lighter skis struggle as we paddled past bumpy Middle HEad section. That's where the ORCA is most fun as it takes everything in it's stride and surfs...
Look forward to see you on the water at some stage.
Have fun!
Jean