The New Chums Trail takes you on a loop walk from Arrowtown, partway up Tobin's Track (there's a cache there too!) then over the ridge and through Chum's Gully to the Arrow Gorge and back to town. Don't worry - you can avoid river crossings in the Arrow Gorge by crossing the bridge and following the Pipeline walk on the way back.
Walking the track anti-clockwise (starting at Tobin's Trail) is easy up, steep down. Clockwise will take you along the Pipeline trail, cross the bridge then a steep ascent up the gully to the top.
If you haven't got time for the full loop track, it's about 30-40 minutes from the parking point to the cache.