Kaea Samson, 8, said his tent blew down on the second night. He woke up to rain and wind and a "blue thing" on his face stopping him breathing.
Ashlee Rankin, 9, said she had sore feet but felt proud of herself. The most memorable part was having to clamber over the dunes to go to the toilet.
Kaivin Zhuang, 8, said the walk was hard but he enjoyed it, especially seeing the shark and "a cool bird". He was looking forward to telling his mum and dad he had walked the length of 90 Mile Beach.
Class teacher Phillip Gibbs said he took his Year 3 and 4 pupils on a camp every year.
"But this time I wanted to do something epic, something they can remember for the rest of their lives. Just think about the number of people who live here in the North but have never walked the length of the beach."
The children were accompanied by parents driving support vehicles with tents, cooking gear and food.
They started at Te Paki and walked 23km to The Bluff on the first day, 31km to Hukatere on the second, 19km to Paparore School on the third, and finally 15km to Ahipara. They walked 10 hours on the toughest day and four on the easiest.
Mr Gibbs said the children took great interest in their surroundings and would have stopped to pick up every shell if he'd let them.
"They had lots of questions, there was lots of talk about the sea. It was a new experience for all of them. There were hard days of just walking, walking, walking, when we couldn't see our destination, but the kids were awesome. I take my hat off to them."
They children offered the odd complaint of sore feet and calls of "are we there yet?", but every time they reached their camping spot for the night they'd all be playing again.
"People questioned whether it was a wise thing to do with 7-8 year olds, but it all went sweet," he said.