I posted about Te Henga (Bethells Beach) before (here), this is one of the best West Coast beaches... of course not a swimming beach for me: just look at the sign!!! But it is a magical place, especially for surfers. The sand is black and you need to walk quite a bit to reach the beach... so make sure that you wear some foot wear, like Flip-flops, (thong sandals, flip flops, zories, slip slaps, thongs, pluggers, toesies, jandals) or you will burn your feet!
The view is amazing, magical and surreal. And almost empty...
The waves are strong, swim between the flags (not that I would, but my husband and the kids do go in, they are stronger swimmers than me, even the my 10 years old boy!).
We took our German wwoofer here, overseas visitors are always amazed at the scenery here.