Whanganui Prison inmate Jim rowed through the night on Saturday - to raise funds for the Heart Foundation.
He was attempting to break the world record of 271,897 metres rowed in 24 hours, using a machine in the prison gym. At first he was only having a two minute break every 28 minutes, just time to scoff a banana or muesli bar before carrying on.
Ten hours into his task it was clear he wouldn't make the distance and break the record - but he kept going the full 24 hours, with slightly longer breaks.
Senior corrections officer Darren Whetton, who has done long-distance rowing himself, said it was a full body workout.
"I know how much pain he's in. To push through knowing the record is gone is quite an achievement."