To put the dive site in perspective, this description of Gordo Banks is from the website of a local dive op:
"Gordo Banks is located 8-10 miles off-shore from San Jose del Cabo. There are different seamounts, while the top of one is approximately 120 feet, the other is at 180 feet.
The dive conditions at Gordo Banks can be quite challenging, due to the depth, strong currents, visibility and heavy seas. Therefore we require all divers (with less than 100 logged dives) to do a local 2 tank dive in the Cabo San Lucas marine park or at the Corridor prior to diving at Gordo Banks."
The emphasis was added by me. Seems like the kind of place where adverse factors can combine quickly.