tools can you do without?
Before answering, perhaps consideration of the recent book "Beyond the Blue Horizon" might be in order. In it, author Brian Fagan (who wrote "Elixir" and "The Great Warming") tells the story of how pre-Columbian sailors learned to navigate without any of our modern methods and instruments.
The Norse, the Polynesians, Alaskans in sealskin kayaks, and other ancient mariners voyaged far and discovered much. How they did it makes a great read. It is humbling for a modern sailor to think of these pioneers heading into the unknown, often believing that hostile gods would suck them down into the jaws of oblivion.
The question remains - how close could a modern sailor come to their methods?
How many of our modern navigational crutches could you get by without?
The question here is not would you, but could you....