Wendy Roesler, Autism Wairarapa Charitable Trust fieldworker, said she was really impressed with the volunteers' handling of an unfamiliar environment.
"A lot of our clients live rurally, and they're surrounded by many places to get lost, like bush, paddocks, creeks and forests," she said.
"Our kids often go wandering if they see something interesting -- if they see a rabbit or hear a tractor, they're off.
"The terrain was completely different to what the volunteers had experienced, but they did really well. We couldn't praise them enough."
The training day started at Wairarapa LandSAR's base at Hood Aerodrome, where they were briefed by Ms Roesler and her colleague Wendy Paterson, and Tam Williams of Alzheimer's Wairarapa, about what to expect when they locate the lost person.
For example, children with autism could be non-verbal, anxious and highly sensitive to touch, distrustful of strangers, and could struggle to articulate their feelings.
"The spectrum is huge -- they have to be prepared for anything," Ms Roesler said.
Fellow fieldworker Ms Paterson said it was vital the rescuer gain as much information from the parent, so they could engage with the child and gain their trust, for example, learning about their hobbies and interests, or capturing their attention with a favourite toy.
Exercise organiser Sam Milligan said each lost person was found by the volunteers within about 45 minutes.
The volunteers learned some valuable skills, such as coping with interference when the radio signal bounced off nearby landmarks and coaxing the lost people from their hiding place as gently as possible.
"It's important not to rush at them," Mr Milligan said.
"You approach them quietly and calmly, reassure them you're there to help, suggest things to them, and make your way towards them slowly.
"A lot of our volunteers are quite big guys, so it's daunting to be confronted with these giants in dayglo jackets."
Ms Paterson said she was pleased to help the volunteers become more aware of autism.
"With autism, knowledge is power -- and now another community organisation has gained a bit more understanding and empathy," she said.
"And having [Wandatrak] is peace of mind for the parents -- they know help is on the way."