Personally, I am not a big fan of the rigs and hull forms that are generally associated with IOR era boats. The rigs had tiny mainsails, and relied on very large headsails in light to moderate breezes which were had to tack and hard to depower. Given that IOR boats tend to be quite tender, that also means these sail plans were quickly overpowered and so required that the boats be reefed earlier than I would consider ideal for a cruising boat, and ultimately require more sail changes and a larger sail inventory than I would consider ideal.
My specific concerns with IOR hull forms changes with each design period of the IOR but derive from the same problem. The IOR tried to predict the performance of a boat based on a limited number of measurements taken in very prescribed ways at very narrowly defined points on the boat. That caused designers to wildly distort the shape of the hull to beat the rule, in ways that made these boats much harder to handle, way less seaworthy, less stable and more significantly, have less predictable stability, uncomfortable in a seaway, and slower than they should be. As a cruiser, these boats also tend to have less carrying capacity relative to their displacement and are less tolerant of the kinds of weight distribution associated with cruising gear. They tend to track poorly and generally make a far less than ideal cruising platform, and are pretty much obsolete for racing. Structurally this was not particularly a great period in yacht construction, as the boats were getting lighter, but designers did not have the tools to properly engineer these boats to produce durable boats, and building techniques were still evolving in not all that great ways.
Before someone objects, I know that people have done amazing things with old IOR boats, but to me that is more about the skill of those people who did those things and perhaps their luck as sailors, rather than any inherent virtues that old IOR boats may have.
As far as the specific boats that you mention, the Contessa 32 design was begun as a very late RORC boat just at the very beginning of the transition to the IOR. The two rules were very similar but the Contessa 32 has some of the residual virtues of the late RORC boats (vs. IOR) but also some of the liabilities as well. The Contessa 32's earned a reputation as being better boats than I would suggest that they are due to their glowing comparison as a yardstick held up to the later of IOR boats of the Fastnet Disaster era IOR boats. In that comparison, there is no doubt that the Contessa 32's really did shine and represented a much more seaworthy choice than the boats they were compared to. But the reality is that they were being compared to one of the low points in yacht design history, and not to more traditional designs, or to more modern designs which have greatly benefited from knowledge available from the post- Fastnet research, and the better design tools, and materials that are available after that period.
As compared to more modern post Fastnet performance cruisers, the Contessa 32's tend to be tender,pitch badly in a chop, are not very good light air boats, are harder to sail in a stiff breeze, and do not offer a lot of accommodations or performance for their length. That said, they do sail well on most points of sail meaning that they have no extreme flaws.
The She 31 was a pure RORC boat rather than being an IOR boat at all. In that regard, it exhibits the worst excesses of the late RORC, short waterline length, pinched ends, fullness in the bow above the waterline, excessively narrow beam and tiny mainsails. To me, boats like these make attractive daysailors, but are way less than ideal for almost any other use I can think of.
I really do not know anything about the Sea Cracker/Tufglass 33.
Jeff
I am not big on the more modern hull designs. I like a bigger fin keel and a skeg hung rudder if I can't have a full keel boat. Would you have suggestions to this kind of cruiser?
