I haven't seen this question addressed.
We own a GB36 Classic, 1976, Journeyman, based in Wilmington, NC.
Last summer we made a crossing of Pamlico Sound from Belhaven to Ocracoke on a day when conditions were forecast to be mild and comfortable. The actual crossing turned out quite different with significant wave action from the port (10 o'clock) direction. The end result was quite a bit of rolling action as we finished our crossing into Ocracoke harbor.
This situation got me to wondering about how much rolling a GB36 can take without turning turtle. Does anyone have any data or experience along these lines. As best I can estimate we seemed to be rolling about 30 degrees either side of vertical and while uncomfortable, didn't seem dangerous. I expect the actual limits to a particular boat will depend on how much weight is above the vertical center of gravity, but perhaps there is a practical limit that should be avoided by changing heading to take waves head-on.