Tour boats slowed. Phones came out. A sleek hull rose and slipped across Bahía de Banderas, close enough for crews and vacationers to stare and film. By mid-morning it had tracked from the shore off Garza Blanca toward the city’s port entrance, with Navy boats shadowing its path. Officials stayed quiet through the day, leaving one simple question hanging over the water: whose submarine was it, and why here now? The scenes on the bay told one story; the lack of answers told another.

Submarine in Puerto Vallarta

Tourists and tour-boat crews were caught off guard Friday morning when a submarine surfaced in Bahía de Banderas, in full view of Puerto Vallarta’s beaches. Videos and photos quickly spread among passengers and workers as the vessel moved through the water. The unexpected sight stirred curiosity across the bay.

The craft was first seen off Garza Blanca beach. It then continued north, passing Nuevo Vallarta before heading toward Puerto Vallarta’s port administration zone, known locally as the API. Those who watched from tour boats described a calm transit and steady pace.

What authorities have said so far

Boats from Mexico’s Navy approached the area to verify the situation. By midday, there was still no official confirmation about the vessel’s identity, flag, or purpose. Authorities had not said whether it belonged to the Mexican Navy or was a foreign visit conducted under protocol.

That silence left residents and visitors relying on what they saw on the water and the clips they captured. For many who work the bay—captains, deckhands, beach vendors—it was a remarkable morning, and an unusual one.

A rare sight on a busy bay

This stretch of water is busy with sightseeing, snorkeling, and fishing tours most mornings. When a submarine breaks the routine, even seasoned crews pay attention. People aboard nearby vessels paused their routes to watch, while others filmed from the shore. The scene was orderly, but the curiosity was obvious.

What we know and what we don’t

We know the path the vessel took and that Navy boats were present. We don’t yet know who owned the submarine or why it transited the bay on Friday. Until authorities issue a statement, those details remain open questions for locals and visitors who witnessed the moment.

Update to story

Mexico’s Navy confirmed that the Chilean submarine SS-20 Thomson is anchored off Bahía de Banderas from August 15 to 18 as it transits north to San Diego, U.S. for the Diesel Electric Submarine Initiative (DESI) exercises with the U.S. Navy. The boat left Talcahuano, Chile, on July 21 with a crew of 45 sailors under Cmdr. Gonzalo Álvarez, and will spend about five months on deployment conducting anti-submarine warfare drills and combined operations.

SEMAR asked all tourist and recreational vessels—including jet skis, kayaks, paddleboards, “bananas,” and parachutes—to keep a safe distance and avoid approaching the submarine, noting that attempting to board or interfere is prohibited. The advisory aims to tamp down speculation and keep maritime activity safe while the Thomson remains in local waters.