No detailed topo is needed for the Abel Tasman. The route is well-tramped. But if you, like us, appreciate a good map while hiking:

Best is Abel Tasman 1:50,000 Parkmap 273-07. Purchase online from Craig Potten.

Alternately, you could pick-up two topographical maps:

Online maps

For advance planning, a map on your computer may be useful. We normally open a map in a separate browser window then flip back and forth between website and map.