At Lake Karapiro on Saturday, McBride and Duggan won two gold medals in the double sculls - the under-16 title in 7min 32.60sec and the under-18 lightweight title in 7min 35.02sec.
It was a remarkable performance because it is only their second competitive season in the sport.
They were always in control in the under-16 event and finished strongly to beat the Craighead crew of Mary Engelbrecht and Erica Taylor by 5sec.
In the under-18 lightweight event they finished 6sec in front of the St Margaret's College crew of Alex Hazlett and Olivia Lissaman.
The pair are members of the Otago Rowing Club and competed in local regattas in the club colours, including the New Zealand championships at Lake Ruataniwha, where they finished fourth in the women's double sculls and fifth in the women's club double sculls.
McBride, who also won gold and silver medals in single sculls events on Friday, will need a new trophy cabinet to house her medals and trophies after finishing the Maadi Cup with three gold and one silver medal.
In the girls under-18 lightweight double sculls four Otago schools finished in the top five.
The Wakatipu pair of Kate Gilbert and Jordan Howell finished third in 7min 51.11sec and collected the bronze medal.
Behind them the Otago Girls combination of Caitlin Buist and Cleo Gilmour was fourth in 7min 51.75sec and the Wakatipu No 2 crew of Gabby Buchanan and Alex Jamieson fifth in 7min 59.78sec.
It was the best performance by Otago schools at the annual Maadi Cup regatta. Crews from the province won a record 13 medals - three gold, four silver and six bronze.
The St Kevin's College girls eight of Johanna and Caitlin Kearney, Bethany Robertson, Georgia Tangney, Eilee Robinson, Lucy Fauth, Katherine Hope, Loren Haggerty and cox Sophie Moynihan proved their mettle by winning a silver and bronze medal.
They finished five seconds behind the Waikato Diocesan College in the under-17 eight in 6min 44.11sec. They were third in the under-18 eights in 6min 54.84sec.
Saasha Bruce (Mount Aspiring) finished third in the girls under 18 singles sculls in 8min 00.10sec.
The race was won by Tessa Young (James Hargest) 7min 58.03sec from Hannah Osborne (Waikato Diocesan) 7min 59.59sec.
The Dunstan girls under-17 double sculls of Caitlin Lowe and Leah Morait won the bronze medal in a time of 7min 35.01sec.
The Wakatipu boys under-15 crew of Michael Foley, Alex Hall, Marco Dyson, Matt Nicholson and cox Josh Speight was third in 6min 48.63sec.
