Indonesia is taking its vaccination drive to the sea as the world's biggest archipelago nation ramps up a bid to innoculate its huge population.
The navy has deployed 60 boats and warships to scour thousands of kilometres of coastline in the hunt for unvaccinated fishermen, from westernmost Sumatra to holiday island Bali and remote Papua.
Among their targets, a navy warship deployed a flotilla of rubber dingeys with crew and vaccines aboard to jab willing fishermen in rickety boats off Sumatra at the weekend.
About 1,000 seafarers have been jabbed since the nationwide programme kicked off last week, although authorities admit they don't even know how many might be out there.
"Bad weather is usually the biggest barrier, but the real challenge now is actually finding (them) because we don't exactly know where they are," said navy spokesman Laode Muhamad Holib, adding that the search area extended 24 nautical miles off the coast.
"We're just combing the sea."
Some Indonesian fishermen spend weeks or even months far from the coast.
Others closer to shore often leave for work before vaccination centres open and return home after they're closed.
"So that's why we're taking the initiative to approach them at sea," Holib told AFP.
The world's fourth most populous nation has been hammered by the coronavirus pandemic.
But so far only about 12 percent of Indonesia's 270 million people have been fully vaccinated with two jabs.
"Our lives depend on the sea," said Sumatran fisherman Adi Putra Hasibuan, who took up the navy's offer.
"We know that the government is supplying vaccines on land but we just don't have enough time to get one."