Bud's Offshore Energy (BOE)

This is a very good article with thoughtful, well informed input:.

“My experience suggests this would be a darned hard leak to remotely determine quickly,” said Richard Kuprewicz, a private pipeline accident investigator and consultant. “An opening of this type, on a 17-mile-long (27-kilometer) underwater pipe is very hard to spot by remote indications. These crack-type releases are lower rate and can go for quite a while.”

Jonathan Stewart, a professor of civil and environmental engineering at the University of California, Los Angeles, said he was surprised the damage wasn’t more severe given how far the pipe was moved.

“My first reaction when I heard that it is displaced so far was that it’s remarkable that it’s even intact at all,” Stewart said.

The type of crack seen in the Coast Guard video is big enough to allow some oil to escape to potentially trigger the low pressure alarm, Kuprewicz said. But because the pipeline was operating under relatively low pressure, the control room operator may have simply dismissed the alarm because the pressure was not very high to begin, he said.