You took my first comment a bit too much by the letter.
Boats are in general designed for a certain use and limits. The CE certification lays that out quite clearly:
Category A: OCEAN – Designed for extended voyages where conditions may exceed wind force 8 (Beaufort scale) and significant wave heights of 4 m and above, and vessels largely self sufficient
Category B: OFFSHORE – Designed for offshore voyages where conditions up to, and including, wind force 8 and significant wave heights up to, and including, 4 m may be experienced.
Category C: INSHORE – Designed for voyages in coastal waters, large bays, estuaries, lakes and rivers where conditions up to, and including, wind force 6 and significant wave heights up to, and including, 2 m may be experienced.
Category D: SHELTERED WATERS – Designed for voyages on small lakes, rivers, and canals where conditions up to, and including, wind force 4 and significant wave heights up to, and including, 0.5 m may be experienced.
That said, I will not call all boats in class 'A' for 'blue water boats'.Let us compare 2 boats, both in 'A', both rather similar in hull design and specs.
However by a closer look, a huge difference.
- Load capacity Jeanneau SO37: 2400Kg
- Load capacity Bavaria 37: 1200Kg.
This includes crew and whatever you add to the empty boat.
Fuel, water, crew, anchor/chain. food, life-raft, dinghy, outboard, ++++++
One of the main reasons I chose the Jeanneau!
There are a lot of other things to consider, the list is just too long to put here.
However I would not consider the SO37 being suitable for a trip in the North-West passage with ice etc, or a long up-wind beat crossing against the wind over the Atlantic. May probably be done, but there I might prefer a different design.
I however had a planned route mainly going down-wind!