Matthew Hood noticed something floating under the dock of the Caribbean Resort and used a net to pull it out. As he pulled the plastic-covered package out of the water, the outer plastic ripped. Inside he saw a powder and immediately called the Islamorada Coast Guard, according to a police report. "Most people who live and sail down here and are aware probably knew what he saw," said Adam Linhardt, media relations director for the Monroe County Sheriff's Office. Hood waited with the package until Deputy Martin Digrius arrived along with the US Border Patrol, the Monroe County Sheriff's Office said. The package contained 25 smaller packages, wrapped in different colors, the police report said. Deputies examined the package and transferred it to federal authorities.The Monroe County Sheriff's Office opened a narcotics investigation. Although the substance is not yet confirmed to be cocaine, police say it "most likely" is. "This happens fairly regularly, about once or twice every year," Linhardt said. "We live in the part of the country where it washes up on the Florida Keys."The origin of the package remains unknown, the sheriff's office said in a statement on Facebook.