Maybe PHRF versus SA/D. And thoe numbers won't give you whethere the boat is tender. I would never intentioally own another tender boat. I think sure footed boats are teh only way to go for cruising.
For example, on our C380, we might have had a relatively high SA/D (relative to other boats of that class... she was no speedster), but she was tender. There wree many times we would not sail her because we knew if we threw out the sails, we would flop to the rail and crap would go spilling everywhere down below.
Now, contrast that with my 400, I can throw out all the canvas in 20 and she slowly falls over to 15 degrees. Instead of falling further to her rail, she accelerates.
I am not sure there is a good way to gauge sure footedness short of test sailing and asking around???
Others may know better about this than me.
I don't know the catalina 38 nor the 400 but for what I can tell from their hulls, they are very different boats. The 400 has a modern hull, not far away from a Beneteau hull and the 38 has an old style designed hull.
I believe that when you talk about the 38 being tender and about the 400 "sure footedness", you are not talking about seaworthiness, or stiffness, but about different hull and sailing philosophies.
Simply, the 400, like the Beneteau and almost all European cruisers, is designed to sail with a 15º heel while the old styled 38 is designed to sail with a lot more heel.
This has nothing to do with stiffness. Stiffness is related with the sail area the boat can take and the wind the boat can handle before it needs to be reefed. To explain this better, let’s take for an instance a J122, a considerable stiffer boat, if compared with the Catalina 400. It can take more sail and almost certainly will reef later....but will sail with a lot more heel, because it is a narrower boat and it is designed to obtain its best performance with a considerable heel. Regarding what I call "sure footedness", it will also be better, because it has a lot more reserve stability (a higher LPS and a smaller inverted stability).
Off course, in what regards cruising boats, for most people, it is a lot more convenient to sail with less heel and a new generation of cruisers was born. These ones maximize that concept, a step further than what it is made in the new Catalinas or on the traditional line of Benetaus, boats that are a mix between a Cat and a sailboat. I am talking about the new Sense series by Beneteau or the new Felling by Alliura:
But less heel does not mean more seaworthiness, or a more sure footed boat, at least in the way I consider it.
Regarding the cruising boats I know, the ones that sail with less heel (not so much as on the Feeling or Alliura) and are more stiff and seaworthy are the RM. These ones besides an impressive safety record, can also be sailed from the interior. Real modern cruising passage makers
RM YACHTS | Accueil
I have considered having one of these and test sailed a RM1200, but even if it has just a perfect interior (to my tastes) and sail very well, it just cannot gives me that extra sailing fun that I find primordial in a sailing boat...I know I know, I am mad
Just mad about sailing.