New Zealand Nautical Charts

Chart of the Tamaki Strait and approaches. The big island in the middle is Waiheke.
Via Land Information New Zealand. Crown Copyright Reserved.

My sister recently sent me some information about nautical charts and it got me thinking that I should learn more about those pieces of paper we depend upon to navigate our way around the Hauraki Gulf in New Zealand. While we inherited a Hauraki Gulf cruising guide with maps in it when we bought our sailboat, we decided to purchase a few "official charts" as well. To make them official you need to buy your charts from either a Principal Chart Agent or a Correcting Chart Agent (they are like the deluxe version of a Principal Chart Agent and have the power to correct your chart with the latest updates). When you buy your chart, they put a special stamp on the back. I find everyone stands up a bit straighter in the presence of the official, special stamp. We got our charts from Trans Pacific Marine in Westhaven. I like the place because the nice guy who stamped our charts for us also gave us a free plastic boatpak wallet which we use to protect our iPad. They cost extra but I asked nicely and said please. My mother was right, good manners do pay off. There are a lot of other retailers you can use - check out the Land Information New Zealand site for the latest list. You can also download copies of charts on their site as well.

So here's some history on nautical charts in New Zealand in case you're interested. Don't worry, you don't have to memorize anything. That's what made history classes so tedious for me in school - having to remember boring facts for tests. I wouldn't dream of inflicting that upon you. My Ohio History class was the worst. The only thing I remember is that there are 88 counties in Ohio. I have never had occasion to use this fact in any sort of practical way since taking that test. So pretty much a useless course. Or maybe I was useless. But back to the subject at hand...

Although the Polynesians were the first to discover New Zealand, they didn't record their travels in writing so it wasn't until the Europeans hit the scene that we got our first maps of the area. It isn't clear who was the first mapmaker. It could have been Jean Rotz who published a map in 1542 for King Henry VIII. He drew a large southern land mass resembling Australia which has a part sticking out that some people think is New Zealand's East Cape. The Kiwis don't really like it when people assume their country is part of Australia so it is a good thing that there isn't great evidence that this is in fact a representation of New Zealand. The next guy on the scene was Jacobszoon Visscher who was part of Abel Tasman's voyage in 1642-1643. He drew New Zealand's west coast from Hokitika to Cape Maria van Diemen and this representation showed up in atlases for the next 228 years. Then of course, Captain James Cook came along with his famous voyage in 1769-1770 when he sailed around both of the main islands and plotted the coastline pretty accurately. After Captain Cook, there continued to be more detailed charts plotted, in particular focusing on the bays, fiords and harbors where ships took on supplies.

And here is a fun fact - in 1855, there was an 8.1 magnitude earthquake in the Wellington peninsula. By comparing a chart from 1849 to one made in 1903, people smarter than me can tell that the harbor entrance became shallower by up to 3.6 meters due to the fact that the peninsula was uplifted and tilted to the west. This is an example of how historical documents can be useful and interesting.

And fun fact number two - did you know that New Zealand has the world's fourth largest Exclusive Economic Zone? If you don't have a clue what I'm talking about, that means that New Zealand has jurisdiction and resource rights over more than 4 million square kilometers of water and sea floor. Given all that water, it isn't just enough to have good charts of your coastline, you also need to map the larger ocean. The earliest one goes back to 1895 and is based upon the Challenger expedition of 1872-1876 which was the first world-wide ocean survey. But because they didn't have the technology we do today, a lot of depth soundings were scattered and only a few large sea features identified. But humans have a way of coming up with new tools and techniques and in the 1990s multibeam echo sounding became a game changer. I'm not really sure how it works. I read a description of it and it seemed a bit too much like something out of Star Trek. But it seems to be the real deal as they've been able to create some very detailed maps as well as discover cool things like underwater volcanoes. If you want to find out more, check out the information about ocean exploration at the NOAA website.

Now that I've learned a little bit more about this history of hydrography in New Zealand, I don't think I'll look at our nautical charts quite the same way anymore.

Note: A great resource for finding out more about nautical charts in New Zealand is Lionel Carter's article on "Charting the Sea Floor" in the online Te Ara encyclopedia which you can find here. 

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