So far just two Westlanders have registered to take part; veteran athlete Steve Maitland of Ross and Whataroa farmer Gary Macrae.
It is understood members of the Hamilton family and several first time competitors from Hokitika have yet to sign up for the event.
There is currently no competitor listed from the Grey district and just two athletes from Westport have signed up.
The current list of entrants has a large group of overseas athletes, coming from as far away as Britain, Canada, Tahiti, Australian, Croatia and Singapore.
Keen athletes have until January 31 to secure their spot in the 243km race, which starts at Serpentine beach, near Kumara Junction, traverses the South Island to the finish line at Sumner beach, Christchurch.
It will be held on February 8 and February 9.