Never been down towards Bulwer. Hori Bay is more a summer spot unless you are spearfishing. Looks like it has kingfish potential off the rocks.
Had 10m+ visiblity in Port Underwood on Sunday, awesome visibility out there. But not much point going for a dive without a Wetsuit at this time of year. You can buy a a decent open cell wesuit for $199
Check out the weekend warrior at the bottom of the page.