There is less than one month to go to New Zealand's best-kept outdoor secret – the Great Barrier Island Wharf 2 Wharf Marathon on October 15.

Currently there is still space for another 100 registrations, so grab a friend and book your place in the race today.

Unlike other marathons, participants can choose to either run, walk or mountain bike this course.

The 2011 Wharf 2 Wharf Marathon provides a full 42.2km course, as well as a half-marathon course for those new to such events.

Both the full and half marathon routes consist of on-road and off-road trails – making the course more diverse and interesting than most.

Participants will enjoy some of the most unspoiled native forest left in New Zealand.

Impressive panoramic views await participants from the summit of Te Ahumata Mountain, historic silver and gold mining site.

Remote white sand beaches, lush bushlands and picturesque settlements dotted around serene island harbours are just a few of the Island's charms.

The Great Barrier Local Board is keen to grow the event and believes it should become the Island's first national calendar event.

Local Board Chair Paul Downie says the event offers people a unique opportunity to experience Great Barrier Island and mingle with locals.

"Although considered a suburb of Auckland by some, we are close to 100km away from downtown Auckland, and enjoy a lifestyle even further removed," says Mr Downie.

Last year's event attracted 125 participants but Mr Downie believes they can comfortably cater for twice that number.

"If you haven't made it across to the Island before, or haven't visited us in a while, this event could be just the excuse you've been waiting for."

"We have some of the best scenery in the country and our small friendly community will see that you are well looked after and made to feel right at home," says Mr Downie.

The marathon will start at Port Fitzroy Wharf in the north of the Island, and conclude at Tryphena Wharf in the south.

All funds raised from the event go to the Island's only primary school - Kaitoke Primary School.

Registration for the event closes on 1 October and can be completed online by visiting www.thebarrier.co.nz.

For further information on the event, travel deals, and accommodation options, visit www.thebarrier.co.nz.