The Spring Challenge is an adventure race for women which began in New Zealand in 2007. It is a team event where 3-women do the entire course together, traveling through the stages as a unit - meaning - it is not a relay team where different team mates do different stages, in adventure racing, the whole team does everything.
The event involves rafting or kayaking, mountain biking, hiking and orienteering.
Because navigation is a factor, each year the event has a brand new course in a different location, so even for the regular participants, it's always refreshed and exciting, plus there's not a big advantage over teams who are new comers to the sport.
The first step of doing an adventure race is having an appetite for adventure and a desire to embark on a challenge. There are 3-main options for the event, 3, 6 and 9-hour options, plus categories within. Decide what suits your ability and taste best, then build a team of 3-women with a shared goal and ideally, similar ability.
Check the gear list and make sure you have or can source to equipment required for the event. You also need a support crew, 1-2 people who can drive a vehicle around the course area meeting you at various points to resupply and change equipment - but this depends on the course design and location, some years the event is 'self-supported', where you don't require a support crew.