Earlier this year, the trailer for a government-backed Taiwanese TV show depicting a Chinese invasion sparked worldwide attention. The ten-part series Zero Day opens by identifying China’s two primary considerations to move on the island nation. The first involves a political power vacuum following an election loss by an incumbent U.S. President. The second is a geophysical consideration and might surprise the average American as being important enough to include in the introduction—the suitability of the ocean currents in the Taiwan Strait for a People’s Liberation Army (PLA) landing.
The Zero Day producers likely took their cue from the Allied landings at Normandy during World War II. Supreme Allied Commander General Dwight D. Eisenhower timed the invasion around ocean tide levels, currents, and wave heights. The landing craft required a low tide and favorable sea state to avoid the beach obstacles and safely deliver Allied troops ashore. Because he had better ocean intelligence than the Germans, Ike was able to exploit a brief break in wind-generated waves to successfully launch the invasion on 6 June 1944, catching the opposing forces off guard.
Since the United States has pledged to defend Taiwan in the event of an invasion by China, it is worth comparing the oceanographic capabilities of the U.S. Navy and the PLA. The naval oceanography community maps and monitors the ocean for the United States with a fleet of six oceanographic survey ships, well more than a hundred underwater drones, more than a dozen interagency satellites, and a global network of fixed and drifting sensors on the seabed, the sea surface, and within the water column.
The primary challenge for U.S. naval oceanography with respect to Taiwan is that its mission is global in nature; therefore, only a fraction of its assets occupies the Indo-Pacific at any time. Compounding the problem is the vastness of the world ocean, large volumes of which are unobserved. More is known about the surfaces of Mars and the moon than about the world’s seafloor, of which 75 percent has not been mapped to modern standards. These data gaps tragically made headlines when the submarines USS San Francisco (SSN-711) and Connecticut (SSN-22) collided with uncharted seamounts in 2005 and 2021, respectively.
China, on the other hand, has focused almost exclusively on the Indo-Pacific, dramatically increasing its oceanographic surveying in the region. A report released in January by the Center for Strategic and International Studies cites hundreds of thousands of hours of Chinese survey vessel operations over the past four years. Most astonishing is the fact that China has 64 active research and survey vessels compared to the 23 operated by the Naval Oceanographic Office and the University National Oceanographic Laboratory System for the U.S. Navy. This mirrors the rapid expansion of the Chinese PLA Navy to become the largest in the world.
Oceanographic surveys are important because the bathymetric and sedimentary features of the seafloor, as well as dynamic changes in the three-dimensional distribution of seawater properties over time, affect the performance of the undersea acoustic and optical sensors used to detect and target an adversary’s assets. Such ocean intelligence is an essential enabler in antisubmarine warfare, mine warfare, amphibious warfare, and naval special warfare—all of which will be necessary to defend Taiwan.
Fortunately, the Department of Defense has kicked off the Replicator initiative to field thousands of attritable, all-domain, autonomous systems in preparation for a future conflict over Taiwan. While the initial tranches of this program are aimed at achieving kinetic effects, Replicator presents a potential opportunity for naval oceanography to make up for its oceanographic survey ship differential with China.
While Zero Day will not air until 2025, the U.S. Navy would be wise not to wait until then to gain an ocean intelligence advantage in the Indo-Pacific.
