In addition, two tandems have been jumping, or slowly standing, on and off their machines to break other milestones.
Shane Flynn and Darren Whetton were looking to set a new record for the longest continuous tandem row for male heavyweights aged 30-39, with the official mark being three days and 17 hours. "The rule is the rower can't stop," said Flynn.
Visser and Grant Satherley were hunting down the record for longest continuous tandem row for male heavyweights 40-49. "Ralph's previously held the longest continuous solo row," said Flynn. The idea came about 12 months ago when the staff got together and did a 12-and-a-half days - or 300 hours - continuous row as a team building exercise. They have trained for eight months to attempt these records, each rowing about 2 million metres, with a quick 10km on lunch break at the prison gym being a regular routine.
Flynn said for the tandem rows, after starting with 45-minute rotations, they had worked out a better system where they row for 90 minutes each at night, then short 30-minute bursts during the day.
"You get three cracks at a 90-minute sleep," said Flynn.
"It's a chance to get the backsides off the seats. It's been an insane week, I'm absolutely shattered. Every time you get up, the knees go."
Around 30 prison staff and other supporters have visited during the week to give support, drop off supplies and have a chat.
The records were expected to be all completed in the early hours of this morning, at which point the group will take photos then head home for rest. To verify the records, there have been witness books signed, detailed logs of times and distances have been kept, and the data will be sent to Concept2 to confirm.
The rowers thanked the Wanganui Marist Rugby Club for the use of their facilities.
The 10-man team looking to break the million metre mark are: Cole Broughton, Thomas Sinton, Gene Peni, Eliesa Nixon, Vince Collins, Carl Priddle, Martha Hura, Pam Burr, Jarrod Hook.