Add another bullet point to the long and growing list of reasons why South Carolina’s coast shouldn’t be open to offshore drilling.

An oil spill anywhere near the Gulf Stream would be a monumental mess, potentially affecting hundreds of miles along the Atlantic Coast and wreaking havoc on one of the world’s most abundant marine ecosystems. Such a disaster would be nearly impossible to clean up, and the costs incalculable.

As reported by The Post and Courier’s Tony Bartelme and J. Emory Parker, computer models reveal that the north-flowing current about 50 miles off Charleston would drive near-shore spills into the state’s broken coastline of marshes, sounds, beaches and barrier islands. Spills caught up in the Gulf Stream would travel north, perhaps coating the Outer Banks or moving farther offshore as the current bends east. Parts of a larger spill could spin off in eddies to the east of the Gulf Stream.

But the Bureau of Ocean Energy Management (BOEM), which is responsible for leasing offshore tracts for exploration, doesn’t include such modeling in its risk assessments. It should.

Meanwhile, President Donald Trump’s administration is pushing ahead with a plan to open nearly all of the Atlantic Continental Shelf to offshore exploration. New leases could be auctioned as early as 2020.

Countless coastal officials, including several who otherwise support Mr. Trump, have vocally opposed the plan. The president should listen.

The Post and Courier looked at more than 1,000 possible scenarios, simulating spills ranging of varying sizes at various locations. The reporters found that a spill in the Gulf Stream would be like pouring oil in a river, with the oil traveling up to about 90 miles per day.

A similar analysis by the National Oceanographic and Atmospheric Administration showed that even a relatively small spill in the Gulf Stream could quickly spread over 152,000 square miles, an area about five times the size of South Carolina. In other words, drilling off the coast of one state could affect many others.

BOEM cannot be blind to such risks.

In the 1980s, California prevented new drilling off its coast by proving that BOEM under the Reagan administration failed to thoroughly consider its stated risk factors. This should be no different.

The risks exposed by spill modeling ought to be reason enough alone to forever ban offshore oil production near the Gulf Stream. And the findings should help solidify opposition along the entire Atlantic Coast.

Even the rosiest estimates of recoverable oil deposits off the Atlantic Coast — none has ever been discovered off South Carolina — pale in comparison to traditional economies supported by tourism and recreational and commercial fishing.

And the potential damage to the ecology of the Gulf Stream and other sensitive habitats, such as the recently confirmed, Delaware-size coral reef off South Carolina, cannot be overlooked.