We're back from our cruise and we had a great time! I don't understand why P&O would visit Noumea on a Sunday especially being the first port of call. I could understand if it was mid-cruise to pick up fresh supplies.
The main town was a real turn-off, not showing to the tourists in a positive light at all. Pretty much the only people in town (away from the morning markets which were terrific) were middle aged men who looked a bit rough. Aside from asking us for money they were harmless. The windows of the shops were all roller shuttered closed so no window shopping either.
We grabbed a few supplies of our own at the Casino Johnson across the road from the dock and it was closed by lunchtime so others missed out. Anse Vata was very busy and a far better place to go. Thanks to those who suggested it.