SAN DIEGO -- A Newport Beach-based Coast Guard crew this week made a 9,987-pound marijuana seizure about 100 miles southwest of San Diego, an amount estimated to be worth $32 million, it was reported Thursday.

The seizure is one of the largest -- if not the largest -- that the Coast Guard has made around Southern California in the past 15 years, Coast Guard Lt. Kristopher Ensley said in remarks reported on the Orange County Register Web site.

The crew on the Coast Guard Cutter Narwhal spotted a suspicious boat Sunday afternoon about 100 miles southwest of San Diego, according to the newspaper. The vessel was sailing northbound going about 6 knots, but as the sun went down, it sped up.

That suspicious behavior, along with the absence of lights on the vessel, prompted the Coast Guard to try to stop it, The Register reported.

"We determined he was a potential drug runner," Ensley told the Register.

During the 3.5-mile chase, the pilot of the suspicious boat started throwing drugs overboard, Ensley said.

"He was able to speed up and outran us," Ensley told the newspaper. "We cannot pursue in Mexican waters."

After passing on the information on the boat to the Mexican navy, the Coast Guard went back and did a search for the drugs using night-vision goggles and flares to help them spot the bails in the dark.

The 12-man boat pulled up 136 bails of marijuana, the Register reported. At 70 to 80 pounds each, they estimate, the bails added up to 9,987 pounds.

In all of fiscal year 2008, the Coast Guard picked up 22,174 pounds of marijuana nationwide, according to the Register.