GTA VI Underwater Secrets: Hidden Treasures Beneath Vice City Waters

Rockstar Games made a bold decision with GTA VI: they turned the ocean from a largely empty expanse that few players bothered to explore into one of the richest content zones in the entire game. Taking lessons from the underwater content in GTA V — which many players felt was underutilized — the developers have packed Leonida’s waters with shipwrecks, treasure hunts, hidden interiors, environmental storytelling, and some of the strangest easter eggs in the entire franchise.

Whether you are hunting collectibles, chasing the next piece of the UFO mystery, or simply want to see what Rockstar built beneath the waves, this guide covers every confirmed underwater discovery as of July 2026. Equip your scuba gear, check the map for dive shop locations, and prepare to explore the 25% of Leonida that most players never see. For related mysteries that bridge the surface and the deep, see our UFO sightings guide.

Getting Started: Diving in GTA VI

Before plunging into the specific secrets, understanding how the diving and underwater exploration systems work in GTA VI will save you time, money, and unnecessary drowning deaths.

Equipment and Vehicles

GTA VI offers a tiered approach to underwater exploration. At the most basic level, your character can free-dive — holding breath for approximately 45 seconds (extendable to 90 seconds by increasing the Lung Capacity stat through repeated diving). Free-diving is sufficient for shallow wrecks and coastline exploration but will not get you to the deeper sites.

Scuba gear is the essential upgrade. Purchased from Ammu-Nation locations in coastal districts for $15,000, the scuba setup provides unlimited underwater breathing and a modest swim-speed boost. The gear occupies the “outfit” slot and can be toggled on when entering water. All Ammu-Nation stores in Vice Beach, Port Gellhorn, and the Keys sell scuba equipment.

For deep-ocean exploration — anything below 80 meters — you will need a submersible vehicle. Three models are available: the Kraken Mini-Sub (single-seat, unlocked through the Strangers and Freaks mission “Depth Charge”), the Nagasaki Nanpaku (two-seat, purchasable from DockTease for $2.2 million), and the Submersible Magnus (military-grade, only obtainable by stealing it from the NAS Vice City naval yard — a 5-star endeavor). Check the Vehicles guide for detailed submersible stats and spawn locations.

The Danger Below

Leonida’s waters are not safe. The marine ecosystem is dynamic and aggressive. Bull sharks patrol the shallows, tiger sharks hunt the reef systems, and great whites cruise the open ocean. The Everglades waterways are patrolled by alligators and the occasional invasive python (a satirical nod to Florida’s real-world python problem). Sharks and alligators will attack on sight. A speargun — available from Ammu-Nation — is the only ranged weapon that functions underwater and reliably dispatches predators in two to three hits. Some players prefer to clear a dive site of predators from a boat using a rifle before entering the water.

Major Shipwrecks

Leonida’s waters are a graveyard of vessels spanning four centuries of maritime history. Each major wreck tells a story and contains unique loot.

The San Esperanza (1642)

The oldest and most valuable wreck in the game. The San Esperanza was a Spanish treasure galleon that sank during a hurricane while attempting to navigate the Gulf of Mexico. The wreck lies at 95 meters depth, approximately 8 kilometers west of Port Gellhorn, requiring a submersible to reach.

The wooden hull has largely disintegrated over four centuries, but the cargo remains: gold bars worth $25,000 each (six total), silver coins scattered across the seafloor, and the Cortez Emerald — a fist-sized gemstone hidden in the remains of the captain’s quarters that sells for $500,000. A skeleton in the wreck clutches a sea chest containing a journal. The final entry, written in archaic Spanish, translates to: “The light came from below. God save us from what rises.” This cryptic message has fueled speculation about a connection to the larger extraterrestrial mystery. For context, review the UFO sightings timeline.

The U.S.S. Leonida (1943)

A Fletcher-class destroyer requisitioned for convoy escort duty during World War II, the U.S.S. Leonida was torpedoed by a German U-boat and sank in 60 meters of water roughly 5 kilometers off Vice Beach. The ship is largely intact, resting upright on the seafloor, and is accessible with scuba gear alone.

The wreck is explorable across three decks. The bridge still holds the ship’s wheel, the radio room contains equipment that emits a faint static signal when approached, and the crew quarters house personal effects that paint a picture of the sailors who served aboard. Of particular note is the captain’s log, which records the sighting of an “unidentified submerged object” moving at impossible speed beneath the ship three days before the torpedo attack. The log explicitly states this sighting was reported to Navy Intelligence and classified.

Two unique weapons spawn at this wreck: the M1 Garand “Pacific Veteran” (a cosmetic variant with period-accurate wood furniture) and the Colt 1911 “Navy Issue” sidearm.

The Vice City Hurricane Fleet (1992)

In 1992, a Category 5 hurricane struck Vice City directly, destroying dozens of vessels in the harbor. Rather than salvage the wrecks, the city simply expanded the port over them. The result is a surreal underwater graveyard directly beneath the modern Vice City harbor, where yachts, fishing trawlers, and cargo ships lie preserved in the cold, dark water.

This site is unique because it combines underwater exploration with urban infrastructure — you swim through sunken vessels while the shadows of modern container ships pass overhead. The wrecks are accessible from several entry points along the Vice City docks. A dive shop near the marina, marked on the map, offers guided tours during daytime hours (a cutscene plays showing your character being briefed about the hurricane’s impact).

Collectibles in this zone include 12 pieces of lost cargo containing randomized valuable items (jewelry, electronics, rare clothing), and the “Hurricane Andrew Memorial Plaque,” which when photographed contributes to a historical landmarks collection.

The Everglades Airboat Graveyard

Not technically a shipwreck, but too significant to omit. Deep in the Everglades backwaters, accessible only by airboat, lies a clearing where over twenty airboats have been deliberately scuttled. The arrangement is unnatural — the boats form a near-perfect circle, and the center of the circle is occupied by an altar constructed from engine parts and alligator skulls.

Exploring the graveyard reveals evidence of a cult that worshiped a “swamp god.” A waterproof notebook hidden in one of the airboats contains what appears to be a ritual text, and a unique melee weapon — the “Swamp Cultist’s Machete” — is wedged into the altar. This location connects to a Strangers and Freaks quest line that begins in a Port Gellhorn bait shop. The quest involves investigating disappearances in the Glades, and the airboat graveyard is the culmination of the mystery.

Hidden Underwater Interiors

Beyond wrecks, GTA VI includes several fully rendered interior spaces accessible only from beneath the surface.

The Smuggler Tunnels

The Vice City coastline is riddled with caves and tunnels carved by smugglers over decades. These passages connect the ocean to various basements, warehouses, and safehouses across the city. The most extensive network runs beneath the Vice Beach strip, with underwater entrances hidden behind coral formations at three locations along the beach.

Navigating the tunnels without getting lost is a challenge — the passages are dark, branching, and unmarked. Players who have fully mapped the network report that it connects to:

• The basement of the Malibu Club
• A back room in the Ammu-Nation on Ocean Avenue
• An abandoned rum-runner’s storage facility filled with intact (and valuable) prohibition-era alcohol
• A submerged room containing a single chair facing a television that plays a loop of static and distorted audio

The last of these is heavily theorized to connect to the ghost encounters mystery, as the audio played by the television includes a voice that matches the spectral NPC found at the Cape Coral lighthouse.

The Underwater Research Lab

In the Gulf of Mexico, roughly 12 kilometers from the nearest landmass, sits a submerged research facility at a depth of 150 meters. The lab — accessible only via submersible through a moon pool entrance — is a multi-room complex that appears to have been studying something retrieved from the seafloor.

The lab is abandoned but powered, with emergency lights casting the corridors in a dim red glow. Evidence scattered throughout tells a story: the research team recovered an object from the seafloor, the object emitted a signal that affected the mental state of anyone near it, and the team was evacuated after what the logs describe as “a mass psychological event.”

The object itself — a perfectly smooth obsidian sphere roughly two meters in diameter — sits in the lab’s central chamber. It cannot be interacted with, but sitting in the room with it triggers increasingly disturbing ambient audio: whispers, distorted radio transmissions, and what sounds like someone crying in an adjacent room that is empty when investigated. The lab is widely considered one of the creepiest locations in the game and a strong candidate for future DLC content.

The Sunken Art Gallery

Off the coast of the Florida Keys-inspired islands, at a depth of 30 meters, lies a deliberate installation: a series of concrete sculptures arranged on the seafloor in the pattern of a gallery. The sculptures are varied — human figures, abstract geometric shapes, and what appears to be a series of reliefs depicting scenes from Vice City’s history.

This is a reference to the real-world underwater art installations found off the coast of Florida and throughout the Caribbean. However, Rockstar’s version adds a twist: one of the sculptures, a seated figure reading a book, has a real, readable book in its hands. The book is “The Secrets of Leonida,” and its pages (flipping slowly in the current) contain map fragments and coded messages that, when assembled, point to a hidden treasure in the Red Hill region.

Buried Treasure and Collectibles

GTA VI’s underwater treasure system is more sophisticated than the simple briefcases of cash found in GTA V. There are several categories of subaquatic collectibles.

Treasure Chests

Thirty treasure chests are placed across Leonida’s waters, each requiring a treasure map to locate. Treasure maps are obtained through various activities: as mission rewards, as random drops from defeated enemies, purchased from antique shops, or found in the world. Each map shows a rough sketch of a coastal landmark and an X marking the chest location.

Chests contain randomized high-value items with a guaranteed minimum value of $15,000 per chest. Rare drops include unique melee weapons (a cutlass, a pearl-handled revolver, a harpoon gun that launches a unique spear projectile), collectible trinkets that can be displayed in safehouses, and pieces of the “Captain’s Regalia” outfit set.

Message in a Bottle

Twenty bottles containing messages are scattered across Leonida’s beaches and shallow waters. Each contains a letter from a different fictional character, together forming an anthology of short stories about Vice City residents. Finding all twenty bottles unlocks the “Message Received” achievement and compiles the letters into a readable book in your safehouse. The letters range from tragic (a farewell note from someone leaving the city after losing everything) to absurd (a shopping list that accidentally ended up in the ocean).

Signal Relayer Collectibles

For players pursuing the UFO mystery, three underwater signal relayers must be collected from deep-ocean locations. These are critical components for decoding the encrypted file obtained from the Everglades Wreck UFO. The relayers are located at depths of 120 meters, 135 meters, and 180 meters respectively, each requiring a submersible and each guarded by aggressive shark spawns.

The deepest relayer sits within a geothermal vent field, where superheated water jets create visibility hazards and damage the submersible if you get too close. Navigating this field while avoiding the patrolling great white sharks is widely considered the most challenging underwater gameplay sequence in GTA VI.

Environmental Mysteries

Some of the most intriguing underwater content is not interactive in a traditional sense — it exists as environmental storytelling, rewarding players who simply stop and observe.

The Sea Monster Skeleton

In a deep trench north of the Bahamas Banks area, the partial skeleton of an enormous creature lies half-buried in the sediment. The skeleton is too large to fit in a single submersible camera frame and must be explored in sections. The skull alone is roughly the size of the Kraken submersible.

The skeleton does not match any known Earth animal. Its proportions — elongated body with paddle-like limbs, a serpentine neck, and a skull with features intermediate between reptilian and mammalian — suggest a plesiosaur. However, careful observation reveals anomalies: the bone structure in certain areas does not match biological norms, and what appears to be mechanical components are integrated into the skeleton’s chest cavity. This has led to the dominant fan theory that the “sea monster” was a biomechanical construct — either an elaborate hoax, an experiment, or something else entirely. The discovery feeds directly into the larger mystery narrative explored in our mysterious locations guide.

The Coral Glyphs

On a reef wall at approximately 40 meters depth, divers discovered a series of symbols carved into the coral. The glyphs match no known writing system in the game world and appear to be artificially maintained — despite being carved into living coral, the symbols are not overgrown. Photographing all twelve glyphs adds an entry to the Close Encounters journal, linking them explicitly to the extraterrestrial mystery.

The Underwater Crop Circle

Off the coast of the Keys, a stretch of seafloor at 25 meters features a perfect geometric pattern pressed into the sand. The pattern is a near-identical match to the crop circle formations found in farmland UFO events, suggesting whatever creates the crop circles operates underwater as well. The sand in the pattern is slightly warmer than the surrounding seafloor, and a faint electromagnetic field (detectable by the submersible’s instruments) lingers at the site.

FAQ

Can I explore the entire ocean freely?

Yes. With the exception of a few story-gated areas (the FIB bunker, certain mission-specific underwater interiors), the entirety of Leonida’s waters are freely explorable from the moment free roam unlocks. The deep ocean beyond the map boundary is blocked by an invisible barrier at approximately 15 kilometers from the nearest landmass — your submersible will warn of “hull stress” as you approach the boundary.

Is there a reward for fully exploring the underwater map?

The game tracks underwater exploration through the “Seafloor Survey” statistic in the pause menu, which measures what percentage of the underwater map you have physically passed within 50 meters of. Reaching 100% is a grind — expect 20-30 hours of dedicated diving — and unlocks the “Oceanographer” achievement and a unique submersible skin.

Do underwater locations connect to each other?

In some cases, yes. The Smuggler Tunnels physically connect multiple coastal buildings. The UFO signal relayers are thematically linked. The Coral Glyphs, Underwater Crop Circle, and Sea Monster Skeleton are all connected to the larger Close Encounters mystery. Rockstar has designed the underwater world to reward holistic exploration rather than treating each site as an isolated discovery.

Will underwater content be expanded in GTA Online?

Given Rockstar’s historical approach to GTA Online, underwater content expansion is extremely likely. GTA Online added the submarine headquarters, underwater business battles, and the Cayo Perico island heist — all of which expanded subaquatic gameplay. Expect GTA VI Online to feature even more ambitious underwater content. Any online-exclusive discoveries will be documented in separate guides as they are added.

What is the most overlooked underwater location?

The Mangrove Maze — a network of narrow waterways threading through the coastal Everglades mangrove forests — contains unique flora and fauna spawns, a hidden moonshiner’s camp, and one of the Signal Relayer components. Because it is technically “water” but not “ocean,” many players overlook it in their diving explorations. The transition zone where freshwater swamp meets saltwater ocean is one of the most ecologically varied areas in the game.

The world beneath Leonida’s waves is vast, varied, and full of surprises. From 17th-century treasure galleons to mysterious alien artifacts, the ocean floor rewards curiosity and patience more than perhaps any other region of the map. Take your time, watch your air supply, and always keep one eye on the shadows — Leonida’s waters are as dangerous as they are beautiful.