Some Ancient instruments
Rough and ready navigational charts were probably used by the Phoenecians around 4,000 years ago. Early civilisations had no idea about the scale of the charts or the size of the land masses- the importance of a country decided its size shown on the chart, and had no relevance to its actual size. The charts were made on sheep or goatskin and were kept closely guarded and secret
also see http://www.brighthubengineering.com/seafaring/23602-a-brief-guide-to-marine-navigational-charts/
Captains rutters, a record kept by old ship captains of weather, depth of water, routes and everything pertinent to navigation, were a prime source of passing of information from one generation to the next. They were sold for enormous sums because they were the only real source of information, and have been around since the fifth or sixth century BCE.
An Astrolabe or a Cross Staff (see pic, left) was the ancient precursor to the sextant, and used for measuring altitude of the planets or stars, particular the north star. (also see www.brighthub.com/engineering/marine/articles/23287.aspx
Sounding reed, first invented in Egypt, was a hollow tube (reed) which was inserted in river or sea water till it touched the seabed. It used the principle of capillarity to determine the depth of water at a particular location was thus available. Obviously this could be used only in shallow water. More accurate was the lead line (c.13th Century) see pic right, which was a graduated rope weighted with lead that was concave at the bottom. The lead was coated with wax to bring up samples of the seabed. One way of navigating was then going from one depth to another based on prior experience. A rutter might read, “Go North till you sound 60 fathoms of white sand, then go North again till you get black mud, after which go North East."
Magnetic compass (c.13th Century) see http://www.brighthubengineering.com/seafaring/23373-marine-magnetic-compass-and-its-use-on-ships/. The main use of the compass initially was to identify direction of wind. It was otherwise used only in overcast conditions when the sun was not visible. As said earlier, it was extremely inaccurate since the concept of variation was not understood.