Eastwood also managed three other top 10 finishes - in the 50m and 100m breaststroke and the 200m individual medley - as well as three Northland age group records and an open Northland one.
Matthew Gordon had the same results as Eastwood, two other top 10 finishes - 50m backstroke and 400m medley - as well as three Northland age group records and an open Northland one.
Madeline Gordon had two other top 10 finishes with a sixth in the 50m butterfly and 9th in the 100m freestyle.
Also producing respectable results for Northland was Hayley McIntosh who came one placing off a medal, finishing 4th in 15 years 200m backstroke.
Northwave's McIntosh also produced five top-10 finishes and claimed two Northland open records along with four Northland age group records.
Whangarei swimming club's Courtney Matich had one top-10 placing, a 4th in the 14 years 200m breaststroke.
Bream Bay's Isabelle Paton placed 5th in the 14 years 100m and 200m breaststroke and backed that up with a 9th in the 50m breaststroke.
Northwave's Ciara Smith, 13, placed 6th in the 200m breaststroke before finishing 9th in the 50m and 100m breaststroke.
Fellow Northwave swimmer Josh Young twice placed inside the top 10, with a 7th and 8th in the 15 years 400m medley and 200m backstroke respectively.
Bay of Islands swimmer David Clarke splashed and dashed his way to 7th in the 16 years 50m freestyle.
Sixteen-year-old Bream Bay swimmer Dylan Sims had three top-10 finishes, an 8th in the 50m backstroke before finishing 9th in the 100m and 200m backstrokes.
Dargaville swimmer Lathan Hutchinson-Walters finished 8th in the 13 years 50m backstroke while Northwave's Annabell Simpson finished 9th and 10th in the 400m freestyle and 200m backstroke in the 13 years category.
Bay of Islands duo of Jake Murray and Bailey Maihi managed two 10th placings between them. Murray finished 10th in the 14 years 50m butterfly while Maihi finished 10th in the 16 years 50m freestyle.
Bream Bay's Paul Linton finished 10th in the 16 years 100m backstroke.
David van der Star also picked up Northland open records in the 100m freestyle and 100m butterfly, while he also picked up 17 years records in the 50m butterfly and 200m freestyle.