NavList:

Lu, you wrote:
"Let us not forget that paper charts have "failure modes" also -- eg, swamping of a navigation desk and destruction of the charts. Why are these not of concern?
And what of blatant human errors (eg, Vestas Wind's)?
My point is simply this: I disagree with simply saying "paper good, electronics bad" without knowing more of failure modes -- especially actual failures."

I agree. In any case, the USCG rule change, if I understand it correctly, doesn't say "carry no paper charts", it simply says that vessels in certain ruling categories are no longer required to carry a full suite of paper charts. That's been a big waste of money for some years now and redundant to the much more capable electronic chart systems. Sure, you may want one wide area chart of your sailing region and one or two harbor charts, but that's all you need in that rare emergency when:

• the electronics fail utterly,
• your backup electronic systems also fail, 
• and your vessel is still maneuverable and basically sound. 

How often does that happen? If literally all of your electronics have been fried, then tell me, can you start the engine? If not, you need a tow, not paper charts. 

The most important backup for any electronics is an "alternate circuit" --a set of systems electrically isolated from the main electronics. This is where the tablets suggested by Jorge Santos come into play. They're off the main power circuit. This is important.

As for celestial navigation, I maintain that it's time to abandon these twentieth century fantasies about evil electronics. Come on, folks, solar-powered calculators have rendered paper solutions, slide rules, etc. utterly obsolete. Good clean fun, yes! But not elements of practical navigation. And once you allow tablets and actual computers into the game, then all that infrastructure of sight reduction, refraction tables, great circle calculations and the rest vanishes in a puff of electrons.

Frank Reed
Clockwork Mapping / ReedNavigation.com
Conanicut Island USA