But it is the smaller, tighter rivers, like the Matukituki and the Dart Rivers, where drivers would be challenged, Blenheim-based driver and race organiser John Derry said.
"We don’t see those speeds a lot because the rivers are so tight," he said.
"We all sort of look forward to getting down to Central where the weather’s a little bit better generally and ... it’s very challenging for us."
Race spokesman Paul Mullan said Mr Derry was considered a favourite in this year’s World Jet Boat Marathon — "the Holy Grail of jet-boat racing" — which begins today on the Waimakariri River and continues over the next week, moving on to Otago rivers.
Mr Derry finished first in the national championships last year, but Queenstown’s Regan Williamson would be knocking on Mr Derry’s door with his brand new 23-foot Canadian-made 1400-horsepower gas turbine boat. Mr Derry had a "whole season under his belt" but Mr Williamson had "a new boat, and apparently it’s very, very good".
Generally, Kiwis driving gas turbines would have a "huge advantage" over North American drivers trying to get gas turbine boats through Otago’s smaller rivers, Mr Mullan said. Mr Williamson agreed yesterday, Mr Derry was likely the favourite, but he said he was "hoping the jet-boat gods are on our side and the boat holds together and we can keep it in the water".
"If we can tick those two boxes, we should be there or thereabouts fishing for the title."
Around Queenstown, he felt there would be a bit of a home-turf advantage.
"We’ve been running our rivers down there — the Dart and the Matukituki and the Clutha — a lot. A little local knowledge always helps."
Testing had gone well.
"It’s a reasonably quick and stable boat. It’s handling really good and cornering hard; I feel really happy with the set-up."
Most of the 45 drivers, from New Zealand, Mexico, Canada and the United States in this year’s marathon arrived in Christchurch earlier this week as boats are set to drop into the water at the Waimakariri River boat ramp for a 12pm race today. The 15-leg marathon makes it to Otago’s Waitaki River by Wednesday for legs eight and nine and carries on to the Matukituki, Clutha and the Dart Rivers before finishing up in Lake Wakatipu’s Frankton Arm with leg 15 scheduled on Saturday afternoon.
Over the course of the marathon, some drivers would experience engine troubles or "just run aground basically and break down", Mr Derry said.
"It’s a race of attrition, really. If you’re there at the start and there at the finish line, you might not have the fastest boat, but it’s all about finishing every leg."
Mr Derry said the number of entries this year was "the biggest numbers we’ve seen in years" despite some Canadian drivers opting not to bear the costs of transporting their boats across the Pacific. The field was largely Kiwi. Southland was the best represented New Zealand region, with nine drivers, while Otago boasted four drivers, he said.
