The three were identified as Liao Guan Yu, Chen Wei Cyuan and Hsu Yung Li. "The defendants have been found guilty beyond a reasonable doubt," presiding judge Efendi Mukhtar read out the verdict.
While there was no mitigating factor to hand down a lighter sentence, the judge said the crime had contravened government efforts to fight illegal drugs and could harm the country's future generations.
According to a statement in the previous hearing, the three men were waiting in Anyer Beach in the province of Banten for the five other suspects to offload the amphetamines from a Taiwanese yacht. The police said the drugs weighed 1 metric ton and were worth Rp 2 trillion (US$143.9 million).
The three remained silent when a translator delivered the judge's verdict. The court will issue another verdict to the other five in a separate hearing on Thursday.