Magnum,
Out of the steels you mentioned, I have only worked with D2 and 440V. The 440V is quite a bit more expensive initially and is definitely more difficult to grind due to its hardness in the annealed state. D2 of course is a "semi-stainless" and I would not use it in a bona-fide coastal region.
I have had very good results with both steels but in my opinion, 440V out performs D2 in a hunting or skinning knife application.
Skinning knives are not designed to cut through bone, that's what saws are for. I have seen more than one blade ruined after some "@#$!" hunter has tried to cut through the pelvis bone of a deer. On the other hand, if a knife's edge inadvertantly chips on a bone, I would be extremely suspect of heat treat. Normal use should not cause this problem.
C Wilkins