The sailing cargo ship Kwai pulled into Kewalo Basin on Tuesday morning with quite a haul — approximately 40 tons of marine debris collected from the Pacific Ocean.

The Ocean Voyages Institute, a nonprofit based in Sausalito, Calif., chartered the Kwai for the first expedition of its kind from Honolulu to the Great Pacific Garbage Patch to retrieve the tons of derelict fishing nets, ropes, plastic floats, bottles and other items after deploying satellite trackers a year in advance to locate them. It is believed to be the largest, single haul of marine debris from the Pacific Ocean over about three weeks.

Mary Crowley, executive director of the nonprofit, sees satellite tracking of debris as a more efficient way to clear rubbish from the ocean.

“This is really kind of a ‘proof of concept’ expedition and we’re very pleased with the results,” said Crowley. “The idea is the more we learn about location of the debris, the more efficient we can be with pickup. I have done monthlong voyages out studying the garbage in the ocean, and we’ve done smaller-scale cleanups where we bring in two to three tons of debris versus the 40 tons we brought in.”

The 138-foot ship departed from Honolulu on May 25, returning Tuesday. It was an efficient trip with the mission of locating and removing the debris as quickly as possible using information from nine trackers and two drones. At one point, the crew found an 8-ton ball of nets and ropes.

The data collected will go to the University of Hawaii’s International Pacific Research Center for analysis, while the nets will go to the HPOWER waste plant for the nets-to-energy program.

Several organizations have focused on the large accumulation of marine debris in the North Pacific Gyre, commonly referred to as the Great Pacific Garbage Patch, about halfway between California and Hawaii.

Last October, Greenpeace sailed through the patch in its Arctic Sunrise, tagging some debris before landing in Honolulu for a plastic pollution campaign. In January, a Dutch entrepreneur’s ambitious ocean cleanup device, a 2,000-foot-long floating, U-shaped barrier with a skirt attached, headed to Hilo Harbor for repairs after malfunctioning while trying to clean debris at the patch.

The debris is actually not a floating patch, but spread across the surface of the water as well as in its depths, down to the ocean floor, according to the National Oceanic and Atmospheric Administration. It includes microplastics, or plastic pieces smaller than 5 millimeters, as well as large, abandoned fishing nets. Ocean fish and seabirds mistake the microplastics for food, resulting in fatal consequences, while marine mammals become entangled in the nets.

Crowley, a lifelong sailor, does not like referring to the area as a patch because she said it sounds diminutive when it is not.

“It’s this huge expanse of ocean,” said Crowley. “It covers a huge area of ocean so I feel people know it by that, but it doesn’t relay the magnitude of the area covered and the amount of debris found in it.”

A crew of 13 from the Kwai, which the institute chartered for the expedition, proved adept at locating and hauling the debris. The cargo ship also was well equipped with sails and cranes to lift the heavy nets.

Part of Crowley’s approach is to recruit vessels from the professional maritime industry to help carry out the nonprofit’s mission. The institute has handed out about 50 GPS-enabled trackers at a cost of about $1,600 each to boaters to tag debris as part of an ongoing project.

Crowley is looking for more funding to deploy more trackers (spheres about the size of bowling balls), and to recruit more vessels, including fishing boats and recreational boats, to participate in future cleanups.

Next year, she plans to launch a more extensive expedition over three months using several vessels, including the Kwai, and even more trackers.

“We can indeed do much more next year, with more time, more money and more trackers,” Crowley said.