Fellow Northlanders Matt McGregor (quarter-final exit in the under-18s), Joe Palmer (first round exit in under-18s), and Joe Moretti (semifinal exit alongside Ruddell in the over-28s), all competed and struggled in the messy conditions.
Most of the Northland surfers moved up a division over the new year, with Scott-Arrieta performing the best. "Manu performed well to make the quarts in the under-18s. He was the highest placed under-16 boy competing in the under-18s," said Ruddell.
"As a coaching and selection team, we're quite excited with the talent we've got. There's going to be some hard selections to come."
However, Ruddell said the results weren't a huge factor in trimming the New Zealand junior bunch, who are managed by Mangawhai's Tony Baker.
"For me as a coach, it was more of a selection observation thing rather than hands-on coaching. All of the age group divisions were taken out by people in the squad, which shows we've got the right people in the squad," Ruddell said.
"[Scott-Arrieta's] got a good chance of making the final 12-strong squad, the under-16s have a couple more competitions before the final team is named, so have some opportunities to shine there.
"He's got a good shot, obviously I can't say too much, but there are a lot of kids pushing hard. He's got just as good a chance as any."
Scott-Arrieta will be expected to put in the hard yards at training before a camp is held in February in Mount Maunganui where he will be put through a variety of tests, before retesting again 12 weeks later.
The New Zealand junior team will compete at the World Surfing Championships in Nicaragua (near Costa Rica) in July.
The World Junior Surfing Championships are an annual event, having been held since 2003. New Zealand have competed at the event since its inception and placed 10th at the 2012 event in Panama.