check out this cool website with free marine charts for New Zealand.

https://wetmaps.co.nz

The developer did a really cool job there and it's an awesome tool for finding new fishing spots.
You can quickly switch between different maps such as marine and satellite.
This makes it easy to check for water depths and then switch to satellite and see what the bottom structure might look like.
You can even switch to a topographical map and check for possible access points and tracks for land based fishing spots.

I really like those maps and use them a lot when exploring new fishing areas.