Universal 5411 11 hp engine
If you search the Cat 30 and the Catalina forums, there was a discussion on the relative merits of the engine recently. Some like it, some feel it is underpowered. To each his own.
We have a 1983 Cat 30 with the 11 hp engine. We sailed it all over the channel islands off California, then down to La Paz, Mexico 11 years ago. Now we sail all over the Sea of Cortez. Nice thing about the motor is that it is easy to work on, uses little diesel, and just keeps going. We plan ahead for tides and weather and sometimes use the sails and engine together. Would we buy a boat with a larger engine? Probably, but it certainly would not be a deal killer. Other factors such as boat condition, electronics, anchoring, etc. are far more important.