Hi Les: Deck stepped spars are less efficient structurally than those that are fixed on the keel and then at the deck. In general, it takes about 25% more mast tube weight to accomplish the same result. So in this regard it is a negative. Second, if you have a dismasting there is not going to be stump left with which to easily fashion a jury rig. On the plus side is the fact that there are no mast collars to leak (they always do), and if you drop a mast, it is usually easier to get rid of the debris. If there were no other issues, for offshore work, my preference would be to have spars stepped on the keel. Steve Dashew