The Blue Lake Regatta has attracted its biggest field in recent memory with almost 700 rowers set to compete in Rotorua.
Defending champion Whakatane Rowing Club will look to repeat its success from last year, which saw it win the prized Dewar Shield.
The Shield is awarded to the club with the most points at the regatta and has a long history in New Zealand, having been contested since 1904.
Rotorua Rowing Club captain Glen Reichardt said about 680 rowers from 21 clubs would descend on the lake tomorrow and Sunday.
"It is one of the last semi-relaxed regattas of the season where clubs can get new rowers on the water and it is a relaxed environment. There is no eliminations and everyone races on the second day."
He said it also helped rowers build up to the club nationals, coming up next month, and annual school events like the North Island secondary champs and Maadi Cup in March.
Reichardt said the Rotorua Rowing Club had not won the Dewar Shield in more than a decade.
He said they were an outside chance this year, with a team of 65 taking part.
"Whakatane are pretty serious about winning it again this year.
"We probably don't have as a good a chance as them but there is always hope."
Reichardt said a team from Melbourne was also coming over to compete before heading to Lake Karapiro for a rowing camp.
He said they had four more clubs competing this year, compared to last year, and the numbers had been growing.
"This is the biggest one I can remember. About seven years ago it was around that 700 mark and we have a target of 1000 rowers, which we hope to get to in the next two years."
He said a terrible regatta a few years ago, marred by bad weather and an influx in wasps around the lake, put a big dent in the event. However, he said the wasps had since been dealt to and the numbers had steadily been growing again.
The MetService is predicting good weather on both days this weekend. The Rotorua Rowing Club hosts the big event each year with support from the Whakatane Rowing Club.
Racing begins at 8am on both days and goes until 5pm.