Roll cages were mandatory, with competitors just milliseconds away from being pinned underwater by their oversize V8s.
The boats handled differently away from the shallow man-made tracks, so training was difficult.
"You only learn by having seat time - it is about getting out there and racing," Thompson said.
"It's not like you can go and practice anywhere. So it's great that the New Zealand Jetsprint Association now runs five qualifiers for everyone, so everyone gets a chance, not just the top guys."
The most successful Hawke's Bay competitor on Sunday at Crownthorpe was 22-year-old navigator Amanda Kittow, competing for a Whanganui team which came second in the 16-crew Group A class.
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