Sorry Big Al, but in my opinion, this is the most ignorant statement made on these boards in a long time.
By your standard no one should be allowed to leave the docks. Even the navies of the world as well as most merchant carriers no longer teach sextant navigation or even carry one aboard, just in case the navigator knew how and had the proper books, as I am sure you would not approve of his use of a calculator or nav computer. Kind of like morse code on boats. The world, much to your chagrin has moved forward.
You can be the best mechanic in the world, but with out spare parts or a machine shop on board, you are dead in the water.
Many of us have sailed thousands of miles (many just dead reckoning or counting the hours and estimating the details) in spite of our shortcomings, failures of equipment, spirit and thoughts....and with no long term affects other than the desire to go back and do it all again,
despite people like you who would legislate to stop us.
Mostly wrong, you cant get a class two merchant marine certificate, if you cant work a sextant. As for the countries that grant them without you being able to work a sextant, they are not on the international sea fairer register, in other words, pass your certificate in Vietnam, and its not valid for any other country, pass it in pakistan, and you can sail on any countries ships.
You may never have to use it, but, what would happen if you lost your GPS. Their is not that much that can go wrong with a well maintained engine, that cant be fixed while at sea. Sure you can have the big end sieze, and a con rod can burst a hole in the crankshaft, but that wont happen to a well maintained engine, it happens when people dont bother changing the oil or the filter. Most of the damage done to engines, is done by the ignorance of the people that own them. But if you cant do the routine maintenance to an engine on a long passage, then either dont use the engine, or dont go.
I was never fond of morse code, but i do know enough about radio, to know, that morse was the way to communicate over the greatest distances. Today its redundant, due to the capability of satelite phones. I did a GMDSS general operators certificate, and a ham radio general certificate, and you can still use a radio to talk over thousands of miles, so why do people take iridium phones, because they dont have the certificates for mf/hf radio, which means, they cant download weather software on their computer, and hook it up to the radio to update it every day, (well they can, but no point buying a radio you cant transmitt on. The cant call for weather forcasts, all they can do is phone a friend.
Dead reckoning is not the easiest thing on a long passage in a sail boat. For a ship crossing the atlantic, from europe to the usa, they often did it without being able to take a sight for the whole five day passage, but for them, at the speed they were going, dead reckoning was easy. In a sail boat, your set and drift, can be as much as your headway, and for a thousand mile passage, if you dont know your set and drift, you could find yourself at the end of your passage, being a thousand miles from your destination.
I have seen it, with people who sailed in my boat, before we left, they knew everything about everything, One guy who sailed on my boat, (in the ocean) had an Royal Yachting Asscosiation offshore certificate, and wanted to do the ocean certificate,which meant a few ocean passages, learn to navigate by sextant, and sit an exam. He wanted to use my sextant, so i let him, first angle he took of the sun, you could look at the sun,and know it wasnt at eighty degrees, you could estimate it at about forty, but he had eight, discovered the mirror was out of o position, so anyway, he gets that fiixed, takes the angle, and i take one to varify, then ask him if he has done all the corrections "what corrections" anyway, i said to him, a while later, have you done your calculations, he said "no, i have to read the book first" he didnt even know the maths involved in it, he thought, get the angle, look at the book and their is your answer, he gave up when i explained to him, when i explained to him, you need to know what sin over cos equals, because he didnt evnen know what sin and cos were.
Thats the way a lot of people are, they think they can do anything, until they have to do it. Then they find out, just because someone else can do it, dosent mean to say you can do it.
Read voyage of the madmen, that gives you a very good insight into things at sea, ok it a by gone age, it was in the sixties, but the sea is still the same, and people are still the same, all we have now, is a few electronic gadgests to make things easier.