After an extensive navigation from Talcahuano Naval Base, the Chilean Navy submarine SS-20 Thomson arrived in San Diego, United States, with the objective of joining the 2025 Diesel Electric Submarine Initiative (DESI) exercise. Over the next five months, the unit will operate alongside the U.S. Navy’s Third Fleet in one of the most significant international trainings in anti-submarine warfare and naval cooperation.
The DESI program represents a high-value opportunity for the Chilean Navy, as it includes training in complex scenarios such as anti-submarine combat against surface units, nuclear submarines, and aircraft specialized in ASW warfare. Operations also cover sea control exercises, combined maneuvers, and submarine rescue drills under NATO protocols, strengthening both operational capability and tactical understanding with U.S. forces.
The Thomson’s departure was marked by an official ceremony in Talcahuano, led by Vice Admiral Raúl Zamorano, Chief of the Navy General Staff, along with senior commanders of the Submarine Force. On the occasion, the professionalism of the Chilean crew and the importance of the deployment to strengthen interoperability with a first-rate navy such as that of the United States were highlighted. Under the command of Commander Gonzalo Álvarez, the unit has a crew of 45 sailors who completed a demanding technical and logistical preparation process before setting sail.
Chile has participated continuously in DESI since 2006, consolidating nearly two decades of joint experience with the U.S. Navy. This continuity has allowed the Chilean Submarine Force to maintain a high level of training, project strategic presence in the Pacific, and reinforce Chile’s role as a reliable partner in regional maritime security.
The Diesel Electric Submarine Initiative was conceived by the U.S. Navy to train with conventional submarines, whose low acoustic signature represents a realistic challenge for its anti-submarine systems. In this context, the Thomson’s participation not only strengthens the Chilean Navy’s tactical capabilities but also provides strategic value by projecting cooperation, mutual trust, and effective deterrence in an increasingly relevant maritime scenario.
Images used for illustrative purposes.-
You may also like: Mountain troops from the armies of the U.S., Argentina, Chile and Peru have officially begun the Southern Vanguard 2025 Exercise
