The eight remaining teams are Broadway Health, Bay of Islands Underwater Club, Dive Zone, Migaloo, three Wettie teams from Auckland and Mount Maunganui Dive Club.
The day's events start at dawn with a spearfishing contest. Competitors must be back in Russell by noon to hand over their catch. The relay race starts in Russell at 1.30pm, with a kids' icebreaker swim setting off at Paihia's main beach at the same time. The first team is expected in Paihia around 2.15pm.
A fish auction will be held at Paihia's Village Green from 3pm with prizegiving at the new fire station from 6pm. Everything from boat cruises to a dive course, meal vouchers and accommodation donated by Northland businesses will be up for grabs at an evening auction, and every team captain goes home with a new wetsuit.
The event is organised by Bay of Islands Underwater Club with proceeds split between Russell Radio, Paihia Volunteer Fire Brigade and Coastguard Bay of Islands.