When you are preparing to gybe, you steadily point the cat down onto a “dead” run, all the time pulling in the main sheet line so that with the wind directly astern, the boom is straight fore and aft down the middle of the tramp’ and the main sail is set “flat” (this is stage no 1). You then helm the cat onto a slight reach on the other tack and the mainsail will simply flip (quite gently) onto the other tack and the mast will rotate onto the new side (stage no 2). Then by steadily bearing more up onto a higher reach and letting out the mainsheet steadily with the change of direction the cat will remain stable and fast throughout the complete operation (stage no 3). You have complete control of the cat and if practiced, you have excellent speed through the entire process.