Christchurch to Hokitika:

An tale of a crossing of the South Island from Waikuku Beach north of Christchurch to Hokitika.

Trip report (Worsley Pass variant):

https://tramper.nz/16357/coast-to-coast-christchurch-to-hokitika/

Route guide (Minchin Pass variant):

http://routeguides.co.nz/trips/679

Kaikoura to Karamea:

A coast to coast across the top of the South Island. 14 days of track and route walking, all on public land or approved tracks. The route crosses a huge variety of country, including the Seaward Kaikouras, Clarence Reserve, Molesworth Station, Nelson Lakes and Kahurangi national parks.

Trip report:

https://tramper.nz/16067/coast-to-coast-kaikoura-to-karamea-part-1/

Route guide:

http://routeguides.co.nz/trips/327

Auckland's Coast to Coast walk

http://www.aucklandcouncil.govt.nz/EN/parksfacilities/walkingtracks/Pages/coasttocoast.aspx