The seafloor around New Zealand is arguably the most complex in the world. This poster shows advances over the last 130 years in understanding and better defining that complexity. Sounding technology over the same period is also shown, advancing from 5–10 lead-line soundings per day with a positional accuracy of 1–2 nautical miles to the present-day 2–3 million soundings per day with a positional accuracy of 5 m. The poster is approximately 70 cm x 100 cm. $28