The 25/26 issue of the German bi-weekly Yacht magazine has a very interesting article comparing a full keel (Vindö 40, 31ft, 1971), a moderate fin keel with skeg (Hallberg Rassy 29, 1981) and a modern fin keel boat (Sun Odyssey 30i, 2008).
They sailed the three boats together in 5 Bft wind and 3 to 5 feet waves to find out which is the most comfortable to sail under these conditions.
They had 3 crews rotating between the boats and all crews reported that the HR and the Vindö are not only more comfortable but the HR even sailed higher and faster than the Sun Odyssey.
(I'm a little disappointed, I expected a German magazine to use 3D accelerometers and data loggers and software to evaluate the boat movements and not just rely on crew opinion
Let me cite the closing sentences of the article:
"The most common argument used to justify the uncomfortable motion of modern cruising boats is that the typical customer (young families, older couples and charter crews) won't leave the marina in winds over 4 Beaufort anyway. For that, these boats are significantly faster in light winds than they predecessors.
The latter may be true. The first, however, should probably be reversed: maybe the reason people don't sail them in rough water is that these boats are too uncomfortable for that?"
"Häufigstes Argument zur Rechtfertigung des unbequemen Seegangsverhaltens moderner Fahrtenyachten ist, dass sie von der angepeilten Klientel - jungen Familien, älteren Paaren und Chartercrews - bei Bedingungen jenseits der 4 Beaufort ohnehin nicht mehr bewegt würden. Da blieben die meisten lieber im Hafen. Dafür seien sie im unteren Windbereich deutlich schneller als ihre Vorgäger.
Letztgennantes Argument mag stimmen. Auf das andere kann jedoch auch der Umkehrschluss angewandt werden: Wird vielleicht nicht mehr bei Seegang hinausgefahren, weil die Yachten dafür zu unkomfortabel sind?"
I have posted about that on the interesting sailboat thread.
The comparison was made on the conditions a heavy boat with a lot of rocker would be at his best and a modern boat at is worst. They also chose for the comparison a particularly tender boat. If they had chosen the slightly bigger jeanneau 33i (much more stiff) I am sure the results would be different, not regarding comfort but speed.
That different performance with lots if wind and short waves upwind is the weak point of many modern mass production cruisers like Hunter, Catalina, Oceanis or Dufour (just to mention some). To go really fast on those conditions you need a much stiffer performance cruiser like for instance a Xp or First. It would no be more comfortable, or at least it will have a completely different motion: A more ample one (pitch) on the heavier boat, a less ample but faster and less soft on the faster boat. The less comfortable motion has also to do with speed. More speed, less comfort.
Anyway that has nothing to do with the type of keel but with the type of boat: If you keep the hulls of the heavier boats and substitute the keels by modern ones, keeping the weight but increasing RM, you would have a similar motion but a faster boat and one able to go faster upwind. Off course, faster would mean also more uncomfortable (at more speed) but that is another story.
"The most common argument used to justify the uncomfortable motion of modern cruising boats is that the typical customer (young families, older couples and charter crews) won't leave the marina in winds over 4 Beaufort anyway. For that, these boats are significantly faster in light winds than they predecessors."
I guess that they forgot to mention two things, the first one is that they should have added to that sentence: "won't leave the marina in winds over 4 Beaufort to sail upwind anyway"
and like that, that's a fact.
The second one is that they should have mentioned also that the price of a boat has more to do with weight than with length (I mean normal boats made with the same materials), so boats like the HR or Vindo, even if with modern and more efficient keels, would be massively more expensive than a boat with the same lenght like the Jeanneau, as they are all the small heavy boats on the market. With that money a sailor could buy a much bigger boat that would be faster and more comfortable. Yes. That is really why the boats on the market are what they are. Neither the designers or the sailors are dumb