Related C320 experience
The C320 is the slightly larger "sister" and handles very well. I have the shoal keel version with the 130% Genoa, Yanmar engine, and a 3-blade prop. I have been generally quite pleased with the boat's design, quality, and performance. A good value for the money.The boats (310/320) are basically designed for coastal cruising and general sailing. Personally, I prefer the C320 cabin layout to the C310, but that's a very individual choice. It is comfortable and conveniently layed out for overnights at at an anchorage/mooring/slip, yet out on the water there are plenty of hand-holds below to allow safe movement. Storage & tankage (fuel, waste, and water) is adequate for this type of cruising -- but not for anything involving extended off-shore work. Access to through-hulls & systems is generally good.The swiftest racer in town it probably ain't, but it has performed solidly in 28-34 knts of wind without being overpowered (reefed in, certainly, the few occasions that I've attempted it.) Not the greatest in light air, but that could be more the Skipper than the boat. A 150% Genoa or a Spinnaker might help if that condition's dominant. A whisker pole rig would be a real plus if you do any extensive down-wind cruising on the Genoa.I've had mine 20-25 miles offshore moving up the coast in the Gulf of Maine taking a steady, all-night pounding in 3-5 ft waves with a short period. Water over the bow quickly drained off. The boat took it better than the crew.With an Autopilot, I can generally single-hand things, though picking up a mooring or anchoring is best done with help. The jib winches aren't really close enough to the helm to handle both functions while tacking unless the Autopilot has the helm under control. The traveler lines can be brought back to the helm to allow trimming the main (e.g., to de-power, handle a jibe, etc).Hope that helps. If buying a used boat, get a good independent surveyor who knows Catalinas to go over it carefully.--Ron