Your 233 will make it across to Catalina. I've seen all type and sizes make the trip as well including watercrafts. The main thing you need to remember, is swells and wave frequency. of course smaller boats don't like large swells, or waves that are really close together.
The trip from Dana point to Catalina is about 33 miles. You need to leave in very early morning when you have very calm water. Don't expect to return the same day, I would stay over night instead of risking the afternoon currents back to DP. As the day wears on the water will get choppy with increased wave heights.
I have a Monterey 245 @ 27 feet and I was given the same advise. I have had my boat in open water with 4 to 5 foot waves and it wasn't fun. If you have other friends with boats, try to get additional boats to make the trip with you. And of course, make sure you have all your life vests, and the rest of your safety equipment on board.