The vessels from a variety of countries were blown up in several seaports across the vast archipelago, which has some of the world's richest fishing grounds.
Navy spokesman First Adm Manahan Simorangkir said today that 35 vessels were sunk by the navy while six were sunk by the coast guard police.
Fisheries Minister Susi Pudjiastuti has sunk several other boats since the new government took over last year after President Joko "Jokowi" Widodo was elected. Dozens of the vessels sunk in recent months were foreign.