Blueback,
When I was very inexperienced, I hit a 6 foot standing wave at Plum Gut head on. It scared the heck out of me. The boat went nearly vertical, and I applied full power out of fear she would slip backwards and dowse the engine. It was really stupid, but part of the problem with the CD-16 is that it is hard to stand up in her cabin when you are a tall person. So you will find yourself sitting down low behind the wheel with poor visibility. I did not realize how bad the wave was until I reached it, and by that time, it was too late.
On another occasion, I traveled between the wave troughs at an angle in 6 foot waves. The waves were so high that they seemed to tower over me when I was in the trough. The boat was kept level by powering into the oncoming wave, and immediately throttling back to allow the momentum of the boat to carry through. It was like being in a washing machine.
I have been all kinds of conditions. The CD-16 does not like short-period head seas of 2 feet or more. I think I would have been able to sustain greater head seas had I had a Permatrim like so many C-Brats recommended. The Permatrim would have allowed me to travel slowly while keeping the bow down. At slow speeds, it is next to impossible to keep the bow down of a CD-16 Cruiser, because she is only 16 feet long, and tends to be stern heavy.
The biggest seas she was in was about 7 or feet, but they were rollers! It was a lot of fun.
Frankly, any more than 3 feet short duration waves, and I would stay at port with a CD-16. Any more than 5 foot waves has the potential for broaching your boat if you do something stupid like going too fast in a following sea, falling off of a wave and sticking the bow at an angle. I can say, however, that on another occasions I fell off of waves, crashed nose-first into the oncoming wave, and a giant wall of water issued forth with no ill effects. She is an amazing boat, because even though she is stern heavy, and has a lot of roll in the stern, her bow is extremely stable. It seemed to me that the more pressure was applied to the bow, the more stable she became.
All in all, the CD-16 Cruiser was a wonderful boat for a novice, because I got to live to tell my stories of my lack of judgement. She really can cover for your mistakes, but really, I would not recommend using her in heavy seas. In other words, if the NOAA issues small craft warnings, stay in port!
Rich