Ghost Wave - Chris Dixon [18]
Coast Survey officer W. P. Blake, who recounted Cropper’s direct words: “The waters were in violent commotion and thrown up suddenly into columns, at regular intervals of four or five minutes.”
Alden’s Constitution sighting had been verified. He dispatched the U.S. Coast Survey cutter Ewing, now captained by Lieutenant T. H. Stevens, to investigate and chart the seamount. Yet for some reason, Stevens did not reach the strange shoal until mid-May 1853. By then, the powerful swells of the wintertime North Pacific were gone, replaced by punishing northerly winds and smaller, but relentlessly choppy seas. Stevens spent five awful days before reporting to Alden:
Sir: I have the pleasure of reporting my return to this place from the shoal to the southward of San Clemente and San Nicolas, of which I have made a thorough examination, having been five days anchored upon it.
The shoal, or bank, is latitude 32 degrees, 39 minutes north longitude, 119 degrees, 19 minutes, 50 seconds west. The island of San Nicolas bears NW by N, distant 46 miles, island of San Clemente bears NE ½N distant 43½ miles. The nature of the bottom is hard, composed of white sand, broken shells and coral. The least water found—ten fathoms—would be about nine, reduced to low water and the character of the soundings, as you will find upon reference to the chart which I send herewith, irregular and abrupt.
The weather, while at anchor upon the shoal, we found different from that which normally prevails upon the coast in the vicinity, bearing a strong resemblance to that upon the banks of Newfoundland.
The current is irregular, frequently setting against the wind and running with a velocity of nearly two knots per hour, producing a heavy sea, and causing the water probably to break in heavy weather, as has been reported.
In his correspondence to Alden, Stevens included the first fairly detailed chart ever drawn of the Bank. It revealed a sort of hilly mesa, roughly twelve miles long and six miles wide, oriented in a northwesterly direction, “in the immediate path of the Panama Steamers.”
The report seemed to bear some good news. A minimum depth of nine fathoms, or fifty-four feet, would not puncture a steamer’s hull, and though waves might break above a fifty-four-foot-deep shoal during a truly monstrous swell, that would be exceedingly rare. Then again, a strong, southerly current of two knots—a half-knot below the average speed of the Gulf Stream—might also be problematic to ships approaching the Bank. When a northerly swell runs headlong into a southerly current, its waves can steepen and stack up against one another into something resembling a line of harried passengers squeezing onto a narrow airport escalator. This is one of the ways so-called rogue waves are spawned.
But Alden also realized that unless he had once seen a procession of giant ghosts from the deck of the Constitution, Stevens had likely missed the mark. While he had surely found a remarkable offshore seamount, there must be an unseen, as yet unfound feature that would throw up towering breaking waves—visible from ten miles distance—in lesser swells.
Alden then christened the shoal “Cortez Bank,” based on an incorrect spelling of Cropper’s ship. Yet in so doing, he forever obscured the ship and crew that actually discovered the Bank: The USS Constitution, “Mad Jack” Percival, and himself.
During the next couple of years, Alden and his men laid the California coast bare. Among their brilliant discoveries were mappings of a tortured seafloor of mile-deep canyons and sunken ridges that linked San Clemente Island with Santa Barbara Island, San Miguel and Santa Rosa with Santa Cruz, and tiny San Nicolas to the long rise today known as the Cortes Bank.
The first known chart and mapping of the Cortes Bank by the United States Coast Survey of