Ruston, Dewancker and Alex Hyland each earned two silver medals and a bronze, while James Brott won two silvers.
Apart from the men's club coxless pair, silver medals also came in the men's senior four (Ruston, Dewancker, Brott and Hyland) and the men's senior coxless pair (Hyland and Brott).
The men's club eight (Thom Simmons, Aaron Maxwell, Lewis Green, Ben McCosh, Dewancker, Ruston, Hyland, Joshua Kelly and cox Phelix Moore) took the bronze.
Simmons also came fourth in a composite crew for Hawke's Bay Rowing Club in the intermediate eight.
The GRC crews were coached by Luke Jenkins, who missed out on racing at this regatta as he was on honeymoon in the South Island.
GRC president Peter Simmons said the results were a culmination of a five-year plan for the rowers, who were working towards medalling in the cancelled 2020 Maadi Cup.
“For the boys who are leaving (for university), it was a way to do a send-off because they missed out on Maadi.
“The expectation for the eight was that they would do well.”
On the back of Ruston and Dewancker's success as a pair, the club had been growing, Simmons said.
This year they expected to send 19 athletes — 11 boys and eight girls — to the North Island Secondary School Champs and to the Maadi Cup.