Before casting out, the two had agreed if they did hook a tuna then they would cut the fish and pack it up quickly on ice, to preserve the high-quality meat.
But once the tuna was on the boat they decided to have it weighed at the Waihau Bay Sports Fishing Club.
The fish tipped the scales to 99.1kg, beating the current NZ women's 37kg line class record of 91.4kg.
The record-breaking capture was recorded by the film crew on board for an episode of Sinden's show, ADOS Addicted to Fishing, which will air later in the year.
Sinden herself was no stranger to breaking records of her own.
Last year, she hooked a 361kg, 4.2m-long broadbill at a secret location off northern New Zealand.
The catch broke the women' all-tackle world record, women's 60kg-tackle world record and the women's New Zealand record.