One reason that denying a global flood is meaningless to me is from multi-disciplinary statements I find all the time: what, really, would be the globe back then? I continually find continents, magnetics, hydrology, etc in such a different form prior to the cataclysm that there is no meaningful comparison. I've even read that it was not the same size, that it was formerly smaller, that our continents are now further from the center through the expansion and cooling of solid magmatics that support them, that there are subterranean oceans. This is not foreign to the Bible, either.
The known world (land) was one cohesive piece back then so that egomaniacs truly could seek domination, and after the cataclysm, the same folks were unaware of entirely detached continents. See Boorstin's history of exploration in THE DISCOVERERS. China did not explore anything for that reason; they already were the one world. Conversely, the middle ages of the West expected an easy connection of east and west; they were in part going on descriptions of one single pangea from before the cataclysm. But when navigators details came back in and the remote view of many continents was drawn out by, for ex., Pellegrini, it was obvious that the whole pangea had been split apart like orange peeling that attempts to do it in one piece.
Palms are buried under deserts; ocean shorelines intact are 1000 ft down in Alaska; there is vegetation encased under the poles; there has been ice at the mouth of Glacier Bay AK as recently as 1760. When that figure is compared to the glacial moguls just south of Olympia WA, on a per-year-retreating basis, there was ice covering Seattle a few thousand ago. There are features all over the place of crust layers being bent over backwards, and of removals. Removals are when the features of a landscape (Grand, 4 Corners) were not built up, but already "up" and removed "down" elsewhere, sometimes thousands of miles. We see the remnant. Things are highly contorted and that was recent. Our hydrologic beliefs must conform.
I find that the expression 'the flood was not global' to be an unthinking entrenchment of gradualism with Ms of years to spend in its bank account.
I believe the Biblical position to be that while the distant universe was 'from of old' (ouranoi...ekpalai, 2 P 3), the earth, its celestial system, and the cataclysm were more recent acts of formation (ge ex hudatos kai di' hudatos sunestosa) 2 P 3), a term borrowed from pottery. Be assured, I get rejected trying to explain that one to YECs!!! Yet it does not validate gradualism nor evolution at all; it simply says there are two theaters, each with their own time scenario.
By the way, the phrase modifying the pottery-formation is theou logo, which is always a very quick event, that I know of, because it is a verbal command. This is also found, for comparison sake outside of cosmology, at the end of Romans where it was the decree (epitagan) of God that the Gentiles believe the Gospel, which we find happening in several sudden events, but even taken collectively is just a few decades. The same epitagan made it clear that this was already embedded in the prophets. Again, each individual explanation of the embedding of that would be sudden, but collectively a few decades are meant.
