The relentless , continuing search for items of interest along the banks of the Ross River by a visiting member of the Darwin Detectorists' Club has resulted in some odd finds : a ganja pipe , several bullets, the cap of a shotgun cartridge and a battered one cent coin . An earlier search of a sandbar in the river with a special underwater metal detector turned up about 20 lead sinkers , a corroded early mobile phone and a l950 thruppence .