I prefer cleaner, rather then dirtier water for Snapper. I don’t know what what Snapper prefer….
I finish work around 3:15pm… Assuming I slack off at 3pm, I doubt I would be on the road before 3:30pm. On a good day it takes 3 1/2 hours to drive to Christchurch, and another say 45 minutes to Birdlings flat. So allowing 4 1/2 hours driving time, I should arrive at the beach around 8pm. So should have enough time to fish the change of light.
Its been nearly 10 years since I fished down that way, But with conditions calm, I might bring my short rock rods rather then surf rods. These same nice looking points around Banks Peninsula, like the look of the ones either side of Stony Bay. Also like the look of Hammerhead point. Could easily spend a decade fishing spots around Banks Peninsula and then would only have scratched the surface.