A community organisation working to restore Maunalua Bay, the long stretch of reef and shallow water between Diamond Head and Koko Head at the eastern end of Honolulu, where sediment run-off and invasive alien algae have smothered much of the coral and native seagrass. Its best-known activity is the huki, a mass hand-pull of invasive algae from the shallows carried out by volunteers standing in knee-deep water, filling bags that are later composted by local farms. Millions of pounds have been removed since the effort began. Open huki events appear on the organisation's calendar and groups can arrange their own; taking part is free and needs only reef-safe sun protection and footwear that can get wet. The office is in Hawaii Kai, about half an hour east of Waikiki.