While boat speed seems to be a popular factor in choosing an offshore rig and while that is a valid point, I personally think that a self draining deck is also something to consider.
Now some vessels may not be suited to this, especially a smaller mono hull due to the fact that the floor has to be raised high enough to a point where the boat may be unstable.
Is this really a consideration for some people venturing offshore with an open center console, non self draining boat? Probably not, I see many boats out offshore which are basically open tinnys.
Another point to consider is positive buoyancy, I assume most boats meet this criteria nowadays, but there may be some vessels getting around that are not compliant.