Here's a simple climbing ladder (have one on each side) which I can unfold in a few seconds when the cat is on its side.
So, I take the ladder near the lower hull in the water ending up automatically near the windward hull. I can grab the ladder ropes for holding the cat down after uprighting

Next the trick is to swing my leg over the centre rope which goes to the front, so under my crotch. When standing up on the wooden bar, grabbing the rope ladder, I am practically on board.





With this procedure I hold my cat automatically in the wind (I'm the brake)