The latitude hook was a favourite of the Polynesians. One piece of bamboo was twisted into a small loop. Another formed a crosspiece, sometimes called the pointer. The distance between the loop and the crosspiece varied with latitude. When held at arm's length with the crosspiece on the horizon and the Pole star in the centre of the loop you were on the latitude of your destination. There were different latitude hooks for different destinations. Making a latitude hook is easy. A piece of wire is a good alternative to bamboo, as shown in Figure 13.3.
One evening when you are on your chosen latitude and before you need to use Crash Bag Navigation, go on deck, hold the latitude hook at arm's length, put Polaris in the centre of the loop, align the crosspiece with the horizon and thereafter you will be able to check if you are on your chosen latitude. If you change your latitude, move the crosspiece or make a new latitude hook.
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