mogan nelson/marek 454cb
These are complicated boats to classify. The design began as an out and out IOR race boat. The prototypes were stripped out deep keel, light weight IOR era boats. They were offered in a variety of configurations from full blown racer to the cruising version with a centerboard that you are looking at.
The cruising version varied quite a bit from the racer, having a full and heavier interior and less sail area, more weight, less draft and less ballast (although I have seen the ballast number published with the CB model with more ballast so I am not sure about that one).
The cruising interior is a reasonably nice layout with some nice features which comes at the price of a wide walk over bridge deck that many people would consider a bad idea for offshore work. The stock interior was nicely finished but a little dark and poorly ventilated. Most of the CB boats have good tankage and storage. They early 454''s and all race models came with port and starboard seaberths. These were converted to storage on later boats. The sharply raked transom makes dinghy handling and docking a bit tricky.
The sailing ability of boats are a mixed bag as well. They have the bagage typical IOR boats of their era. They are not terribly stable, the flat at the bow pounds when beating into a chop, the tend to roll a lot downwind, and have that roll and lurch typical of the IOR boats of that era. For a cruising boat they are moderately fast. Their PHRF rating is a little misleading in that the have pretty good downwind speed with the centerboard up and the full spinacker flying. Like most IOR boats of this era the 454 has a comparatively small and high aspect ratio mainsail depends heavily on very large foresails. To get a reasonable performance in light air, and safe heavy weather capabilities 454''s really need a pretty large sail inventory (4 jibs [storm, #3, #2,#1]and a spinacker) for offshore work. The spinnakers on these boats are huge and really do not lend themselves to being shorthanded. Without the huge racing spinackers these boats are quite slow downwind and would rate substanially higher. In addition these boats have really bad seakindliness dead down wind, rolling pretty wildly, expecially with a chute flying. Because of the big headsails, these are a boat that requires a strong and athletic crew to take advantage of the speed potential of these boats. One thing that would be a deal killer for me on these particular boats would be a cabintop mounted traveller.
As to whether these are offshore boats, that is a hard question. In some ways they are very good offshore boats and many of them have done the islands and Atlantic routes. On the other hand the hull form, cockpit size, and rig are less than ideal. The build quality seems to be quite good as compared to the ''normal'' Morgans.