Current State of the Gulf

So in trying to get an idea of the current state of the Gulf of Mexico and the impact of oil drilling, I started digging through the USGS Energy Resources website. I've looked at the USGS store and want to purchase a few maps from there. Another resource found was the abstract of a paper (the full paper is behind a paywall) detailing the impact on the Louisiana coastline from resource development and extraction, with emphasis on the rate of land loss. All of this information (and more) will make it into the campaign setting in some way.
One characteristic of the Gulf of Mexico coast is that the shoreline has changed dramatically. Sea levels have risen roughly fifteen meters (or fifty feet for any Americans in the audience). The bottom half of the Florida peninsula has vanished beneath the waves. Although not on the map, portions of Cuba are high enough to remain inhabitable. The large blue streak on the left is the Mississippi River basin. Other portions of the current landscape underwater are the shaded areas of the map.

Regarding land loss in Louisiana, it would be very easy to assume climate change was the culprit. However, the information from a survey of records shows that sea level rise only contributes 3mm/year to the shifting shoreline. A majority of the land loss (10mm/year) is the result of tectonic subsidence along the Gulf of Mexico. This discovery led me to the USGS website to find information about the plates beneath the Gulf. The crust under the Gulf of Mexico appears to be part of the North America plate, but there are several regions of subduction around the region.  The Caribbean plate borders to the east, but more interestingly, the South American plate starts nearby, but geologists have yet to pinpoint the boundaries of the North American & South American plates. This uncertainty means that the Gulf could harbor more tectonic activity that one would assume. Again, I hope to acquire a map of the sea floor to learn more.

Gulf oil infrastructure

So where are the oil rigs in the Gulf of Mexico? After the tragedy of the Deepwater Horizon, the ecological danger posed by oil spills was made abundantly clear. The USGS has a map that shows the location of active and capped oil wells in the Gulf of Mexico. Looking at the map, I'm surprised that oil spills aren't a more common occurrence. Also, you can see the effect of Florida's existing (and tenuous) ban on offshore drilling. So if those structures were allowed to fall into disrepair, then oil spills would affect the Gulf Coast. The prevailing currents would carry oil eastward along the shore, although the current further away from shore would take the oil the other way, in a counter-clockwise direction.

Prevailing Gulf Currents

Of course, after a nuclear war and the dissolution of society, those rigs probably wouldn't be left to decay peacefully. I can easily envision wildcat operations or violent clashes over the viable sources of crude oil remaining fairly intact in the gulf. Additionally, skimming operations with booms collecting oil from slicks floating on top of the water might produce enough petroleum to justify running a small flotilla of both tankers collecting the oil and gunships protecting the operation. I imagine such a scheme as the source of Uncle Bayou's wealth and power. Trying to protect his energy empire provides plenty of plot hooks to draw the player characters into the action and intrigue in this post-apocalyptic fiction.