One day last month, as dawn broke over Tomini Bay, Central Sulawesi, nothing could be heard save the howl of the wind and the splash of waves. Flashes of light were spotted from a ship offshore. The light grew brighter as it came nearer. When it reached shore, several people unloaded dozens of sacks as they pounded heavily on the sand. Cargo unloaded, the vessel headed back out to sea—in low gear to reduce engine noise. The sea was again...