But in reality it wasn't scary at all.
First there was a friendly welcome from Mountain Valley's owner, Clive. Then rafting guide Dion said the trip would be sedate enough to be able to wear whatever we wanted under some wet-weather gear.
Trips to the sections of the river that have grade four and five rapids lock you in, geographically speaking, for half a day, so we were offered the option of an easy drift through grade one and two water where it's quite possible to try your luck at grabbing a trout along the way.
The part of the Mohaka we were on meanders beside steep cliffs and sometimes sweeps of gravel.
It felt as if we barely disturbed the wildlife, other than sparking the curiosity of the fantails which followed us down the eddies.
Dion has rafted the river since the 80s and has lived near it since before that, which made the trip all the more entertaining with a swag of Barry Crump-style yarns.
The only parts of me that got wet were my feet and my imagined school dorm morphed into an immaculate riverside cottage with the world's best shower.
Rum at the lodge's central block completed the defrosting process and paddling on the river meant there was little left of a huge feast cooked by Sue.
To top things off, we had ventured out with a basket of yummy breakfast provisions.
While these days Hawkes Bay is best known for its wine it has been New Zealand's fruitbowl for a lot longer.
For generations visitors have been able to enjoy orchards and roadside stalls selling produce.
Now the locals have started turning this bounty into jams, jellies and relishes, cheeses, gelato and smoked seafood.
Boutique food businesses have sprung up everywhere.
Hawkes Bay Incorporated has a food-trail map of producers and visiting them is a great way to see the countryside.
But if you're pushed for time or petrol you can see most of them in the food trail at the Hastings Farmers' Market in the showgrounds every Sunday morning. In summer people display their wares under the trees and in winter they move inside.
Like any market it's a fun way to while away an hour or two and do some food gathering and tasting.
The bay also has an art trail of 50 galleries and studios.
Wine Country Gallery in Havelock North, run by artist Jane Gray, was superb. I wasn't expecting such a variety of high-quality contemporary art.
It has the added pleasure of being a very personal selection of art because, as Jane says, "It's not in here if I don't like it."
On a smaller scale there's a delightful wee gallery hidden away in Napier dedicated to works on paper.
Aptly named Paper-works, it has prints, originals and etchings by artists that include Dick Frizzell and Don Binney.
An added bonus is that works available for as little as $100.
Filled with art, fine food and that righteous glow from outdoor adventure in winter, I'd have to say wandering off the wine trail was a fine idea, although I don't think I'd want to stay off it all the time.
GETTING THERE
Air New Zealand has flights every day from Auckland to Napier, taking 55 minutes. On the web, www.airnz.co.nz
GETTING AROUND
Rental cars can be hired from Hertz or Avis at Napier Airport. On the web, www.hertz.co.nz
ACTIVITIES
Mountain Valley is 50km from Napier, on McVicar Rd, just off the Napier Taupo Highway. Transport from Napier or Taupo can be arranged. www.mountainvalley.co.nz
FURTHER INFORMATION
www.hawkesbaynz.com
* Susannah Cullinane explored Hawkes Bay as guest of Hawkes Bay Incorporated, Air New Zealand and Mountain Valley.