An abandoned boat recently spotted in Puerto Rico contained a stunning find: $3.7 million in cash inside several duffle bags.

Agents with the U.S. Customs and Border Protection (CBP) spotted the vessel leaving the coastal town of Fajardo with no lights headed towards the U.S. Virgin Islands this past Sunday. The boat suddenly turned around and headed back to Fajardo, making a stop in Rio Fajardo, a news release said.

The Border Patrol, Border Protection, Air and Marine Operations and Drug Enforcement Administration (DEA) agents followed and saw people inside the vessel unloading duffel bags. They eventually escaped from the boat and investigators found five duffle bags filled with cash.

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A loaded Taurus .40 caliber pistol and 63 rounds of ammunition also turned up on the boat. The feds seized the cash under failure to declare and bulk cash smuggling laws, CBP said.

“We remain committed to working with other federal and local law enforcement partners to detect and deter smuggling attempts throughout the Caribbean,” Johnny Morales, the director of air and marine operations for the Caribbean Air and Marine Branch, said in a statement.