Martin and Jack Andrews, 43 and 19, were from Pudsey and were found in the Calder and Hebble Navigation Canal near Cooper Bridge in Huddersfield on Saturday evening.
The pair had been taking part in an activity called magnet fishing, in which people trawl waterways with magnets to retrieve metal items such as treasure.
The alarm was raised just after 11am when a dog walker spotted their belongings including a jacket, camera and keys beside the canal and alerted police, who sent an underwater search team and retrieved the bodies at 7.20pm.
Their Jaguar X-type car keys were traced to an address in Pudsey, where Martin's wife and Jack's mother confirmed they had gone fishing.
They had left home at around 6.30am and had been expected back at lunchtime.
The circumstances are not thought to be suspicious and the coroner has been notified.