He repeated his attempts to find his way back on Saturday morning and, after failing a second time, sought refuge in the Totara Flats hut. He managed to start a fire and dry his gear before striking out again the next day.
"It wasn't until Saturday that I really started worrying. I knew I was in trouble but I just didn't know how much. I knew death was a possibility but I was determined not to think that way,'' Mr Richards said.
He said he had left the hut on Sunday about noon with a sore back and legs, and had been quickly drenched after deciding to stay close to a swollen river so he could be easily sighted.
He had left a note at the hut, as he had at his campsite, and about an hour later heard rescuers approaching.
"I can't thank all the searchers enough for getting out there to find me at the drop of a hat. I didn't realise I was overdue by almost 24 hours and yet it seemed like they'd found me so quickly.
"I can't thank them all enough.''
Wairarapa police Sergeant Peter Rix said friends of Mr Richards had reported him overdue about 6pm on Saturday after he failed to rendezvous with them at Mt Holdsworth Lodge an hour earlier.
A Land Search & Rescue team was assembled and a helicopter crew eventually found Mr Richards about 3pm on Sunday near the Totara Flats hut.
Mr Rix said about 20 police hours, 90 volunteer hours and two hours' helicopter flying time were spent in a search and rescue effort that involved 15 people, including two police officers.
Mr Richards said his experience and survival were a cautionary tale for other beginner trampers like himself, who "should not go out alone and never, ever deviate from their planned route".