According to Catana's brochu
...
Another important safety factor is the shape of the hulls and
the possibility of lifting up the daggerboards in heavy weather,
which allows the boat to side-slips rather than raising a hull.
Thus she can cope with the largest waves and heaviest squalls.
Without immersed anti-drift plan, the Catana can glide smoothly
on a steady plane, without the "trip" risk of a fixed keel.

Does this really make a big difference in heavy weather as
compared to other catamarans with fixed fins ?

Does it eliminate the need to use a parachute sea anchor under
the worst conditions or would you use a sea anchor anyway ?