NavList:

Sure.  These may be good ideas.  Over time the watches that are less waterproof fail to proceed and get replaced.  The aim is to have back-up systems, ideally ones that can perform the same useful functions as those being backed-up, but not vulnerable in the same ways.  So motors to augment sails, oars to function in the place of recalcitrant outboards, kerosene (paraffin) lamps in case the electricity supply goes (or just to preserve battery power), tinned food if the fish don't bite, and so on.  Traditional methods of nav for when the GPS has an issue.  Nah, forget that one.  Nav is a whole mindset, not just an alternative methodology.  Its about being aware, in a wide sense.

Frank, Frank.  Impractical in practice.  Those things take quite a while from cold to become functional, then continue to chew through those little AA or even worse AAA cells at a quite unsustainable rate.  You couldn't carry enough cells to cross an ocean with.  They are only for occasional use, assuming the nearest Wal Mart is always close-by.  Yes, you could use rechargeable cells, with a solar system to do that, and then you have another system to maintain while you wait for it to fail.  I'll say it again, sailboats provide terrible environments for even robust equipment.  Sailing involves a lot of fixing stuff or learning to do without it.

 

I think this person would be much better advised to learn to navigate, and not be dependent on electronics to do it for him/her.  

Let's remember that the basis of nav is a DR plot.  Knowing where you start from, then tracking movement over time.  Everything else is just ways of checking that plot.  This is the real reason why GPS is so potentially dangerous - when it fails, or the necessary supporting systems fail to allow it to do its miraculous stuff, then the poor silly sod has no idea at all, instead of having quite a useful idea that is regularly updated, albeit a derived position that can probably stand some refinement.  Dependence on GPS doesn't encourage people to look carefully at their environment on an ongoing basis and think constantly about how what they see can be useful information.  Traditional nav does this.