Sport climbing 45 minutes from Nelson? The Beach is a convenient crag-let 45 minutes East of Nelson with a 15-20 minute coast scramble approach. It currently has about a dozen short sport climbs ranging from 13 to 20.
On your first visit you should plan on being there no more than 1.5 hours each side of low tide. With experience you can expand on this.
This free PDF also includes driving directions and approach instructions.