Armed with just a magnet and a rope, friends Matt Miller and Matt Leggett have found everything from guns to safes in Norfolk's rivers.
But their unusual hobby is more than just about hunting for treasure - the pair are also helping to slowly clear up the county's waterways.
And in the past few months their discoveries - which are filmed and posted on their Facebook and Youtube channels - have revealed just how much is lurking beneath the water.
'The amount of stuff you find is incredible,' says Mr Leggett, 23, from Spixworth.
'There's always a bit of suspense when you throw your magnet into the water because you don't know what you are going to pull out.'
The former Reepham High School pupils only started magnet fishing in September last year after previously trying their hand at metal detecting.
But in the space of a few months they have found weapons, safes and jewellery.
In November, while magnet fishing in the River Wensum, they pulled up a sawn-off shotgun.
Months later they found the remains of a double barrelled shotgun in a river at Old Lakenham.
The duo were back out along the Wensum on Saturday where they were filming another instalment in their 'Dippy Detectorists' series, which follows their exploits.
In just a few hours they had pulled out enough scrap metal to fill a wheelbarrow, ranging from old bed frames, car parts, a saw and a lantern.
Despite most of it being worthless, Mr Miller, 24, from Haveringland, said they never dump the items back in the water or leave them on the riverbank.
Instead, they collect it and Mr Miller, who runs his own gym equipment business, takes it down to a scrap yard once a month.
Mr Leggett said: 'There is no point taking it out of the river if you are going to leave it on the side.'
The magnets used by the pair only cost around £70 online, but have a pulling force of up to 300kg.
In December their magnets pulled up a safe on Hellesdon Mill Lane, and when they cut it open they found a handful of coins dating back to 1806.
• To follow their adventures, search for The Dippy Detectorists on Facebook or on Youtube.
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