If its anything like the C36 wing keel its not
tender at all. In fact, just the contrary. The wing keel is heavier than the already substantial fin keel. I have the standard mast on the C36 (Wing Keel) and I have very rarely gone over 15-20 degree's and thats with full main and a 135 Jenny flying in over 20-22 knots hard on the wind (tall rig and 150 might be just a bit different but its still fairly stiff)Tenderness has a lot more to do with just the keel configuration, whether its wing or fin or full, etc. It has to do with sail area, sail balance, (not to mention blown out sails don't help) weight distribution, (Ratio of keel versus overall weight) and also very important is the shape of the hull. These Catalina's have a pretty good hull form stability, in other words, they might go to 10-20 degs, but once there "lock down" and it takes a LOT to get them much further, you'd almost have to try and even then its tough. All in all these mid 30's size Catalina's are a moderately stiff boat. Wing or not.