THE blue-painted wooden prau, with a tarpaulin shade in the middle, was cleaving through the sea towards Onrust island, leaving behind the coast of Muara Kamal in North Jakarta. Its two 40-horsepower engines roared while it plied the waves, one Tuesday evening last July.

Under the shade, Sardjono Kartosoewirjo, 53, sat cross-legged on the boat’s floor. There were no chairs on the prau, which was now racing north. “This is the first time I�