Trigger Location & Requirements
The Treasure Hunter stranger mission triggers at the Mangrove Marina dock on the southern edge of the Leonida Keys between 6 AM and 2 PM. The NPC — a sun-weathered retired ship captain named Captain Jack Reeves — sits on an overturned boat hull mending fishing nets. He's researching the shipwreck of a fictional 1720s Spanish galleon called the "Santa Catalina" and needs a dive partner.
Captain Jack has a salt-and-pepper beard, a faded Navy tattoo on his forearm, and wears a worn deck jacket over swim trunks. His dock area includes nautical charts pinned to a corkboard and a small research boat. He appears after completing 8 story missions and requires the player to own scuba gear (purchased from the Dive Shop for $200).
Walkthrough
Captain Jack's treasure hunt spans 4 dive expeditions to progressively deeper sites. Dive 1: a shallow coral reef (15m depth) where you photograph the galleon's scattered debris field and recover a ship's bell. Dive 2: the mid-section wreck (30m depth) where you retrieve a captain's log from a sealed chest — the log contains clues to the treasure's specific location. Dive 3: a deep trench (45m depth) containing the galleon's cargo hold with gold bar samples.
Dive 4 is the climax — the galleon's treasure vault at 55m depth in an underwater cave system. You navigate through narrow passages with limited air, following Captain Jack's radio directions. The vault contains the Santa Catalina's treasure: a gold-encrusted compass, jeweled navigation instruments, and stacks of gold coins. You load treasure into a lift bag that surfaces to Captain Jack's boat.
Rewards & Payouts
Each dive pays a share of the recovered treasure: $5,000 (Dive 1), $10,000 (Dive 2), $15,000 (Dive 3), and $50,000 (Dive 4) — totaling $80,000, making this the highest-paying stranger mission chain in GTA 6. Completing all 4 dives unlocks the "Deep History" achievement and a unique gold compass accessory that functions as an underwater navigation aid.
The gold compass displays a heading indicator while diving, showing direction toward nearby underwater points of interest (shipwrecks, dive sites, submarine parts). It also grants a 15% extension to underwater breathing time when equipped. Captain Jack gifts you his personal dive boat — a modified fishing vessel with sonar and an anchor system — which spawns at any owned marina dock.
Outcomes & Consequences
After the treasure recovery, Captain Jack publishes his findings in an in-game academic journal that appears on the internet. A news segment covers the discovery, and the Santa Catalina wreck site becomes a marked dive location on the map that other NPC divers visit. Captain Jack's marina area gains a small museum display with artifacts from the expedition.
Captain Jack becomes a permanent phone contact who texts about new underwater discoveries — these texts function as hints pointing toward submarine parts and other underwater collectibles. His dive boat remains available at marina docks indefinitely, providing a free high-quality vessel for any water-based activities.
Missable Content Warning
Captain Jack spawns reliably during valid hours. The dives must be completed in sequence, with each requiring a separate visit (you cannot chain all 4 in one session — Captain Jack needs time to analyze findings between dives). Allow at least 24 in-game hours between each dive attempt.
Scuba gear is a prerequisite that must be purchased before starting. If you don't own scuba gear, Captain Jack mentions the Dive Shop and the mission doesn't proceed. No content is permanently missable — all dives remain available until completed.
Character Analysis
Captain Jack Reeves is GTA 6's most avuncular NPC — a genuine maritime enthusiast whose passion for underwater archaeology is infectious. His radio commentary during dives blends historical knowledge about the Spanish colonial era with personal anecdotes about his Navy career and retirement to the Keys. He calls the player "partner" and treats the treasure hunt as a collaboration rather than an employer-employee arrangement.
His character represents the Leonida Keys' retired maritime community — knowledgeable, weather-beaten, and slightly lonely after a life at sea. Unlike most GTA NPCs, Captain Jack has no ulterior motives, no criminal connections, and no satirical edge — he's simply a man pursuing his lifelong passion for underwater discovery.
Tips & Strategies
Upgrade lung capacity at the gym before starting the dive chain — Dive 4's cave system at 55m depth requires extended underwater time. The advanced scuba gear from the Submarine Parts collectible chain (if completed) provides additional breathing capacity. Bring a flashlight for Dives 3 and 4, as deep water visibility drops significantly.
During Dive 4's cave navigation, follow the air bubble trails that rise from cracks in the cave ceiling — they indicate the path toward the treasure vault. If you run low on air, emergency air pockets exist in two locations within the cave marked by phosphorescent coral. Captain Jack radios warnings when your air drops below 30%.
History in the GTA Series
Underwater treasure hunting appeared in GTA V through the submarine pieces collectible and the Merryweather heist's underwater approach. However, a dedicated multi-dive treasure expedition as a stranger mission chain is new to GTA 6. The format draws inspiration from Red Dead Redemption 2's treasure map system while leveraging GTA 6's underwater mechanics.
Captain Jack's dive boat reward continues GTA V's tradition of stranger missions that provide unique vehicles — GTA V's Omega provided the Space Docker, and Maude provided bounty hunting access. The gold compass navigation tool is the first functional underwater HUD element earned through a stranger mission in the franchise.
The Treasure Hunter network of informants spans the entire Leonida coastline, with each informant specializing in a different type of hidden content — underwater caches, buried containers, or concealed room entrances behind destructible walls in abandoned structures.
FREQUENTLY ASKED QUESTIONS
Where is the Treasure Hunter?
Captain Jack Reeves sits at the Mangrove Marina dock on the southern Leonida Keys between 6 AM and 2 PM. You need scuba gear ($200 from the Dive Shop) before he'll start the mission.
How much does the full chain pay?
$80,000 total across 4 dives — the highest-paying stranger mission in GTA 6. The final dive alone awards $50,000.
How deep do the dives go?
Progressively deeper: 15m, 30m, 45m, and 55m. Upgrade lung capacity and consider completing the Submarine Parts chain for advanced scuba gear before attempting Dive 4.
What does the gold compass do?
It shows direction toward nearby underwater points of interest while diving and extends underwater breathing time by 15%. It also functions as an accessory item.
Do I get Captain Jack's boat?
Yes — completing all 4 dives grants his modified fishing vessel with sonar and anchor system. It spawns at any owned marina dock and is a permanent addition to your vehicle access.