NavList:

You can read more about this here. As reported, the current owner supposedly chose to abandon the vessel because he was without power in a busy sealane --he was worried about being run down. This was not a navigation issue (navigation in the sense of position-finding), and the position of the vessel at the time of abandonment is known.

Setting aside this incident, what is a good backup? Is it a sextant?

I always ask my students at the beginning of any celestial navigation class: What's the best backup to your GPS system? Not always, but in a majority of cases, someone will guess --because of the way I pose the question-- that the answer is another GPS. We do need to worry about main power going down. We also need to worry about singular faults in one system. If your main GPS fails, the best backup is GPS. That's why we should always have a few cheap devices like smartphones charged up and available and at least one small-scale, wide-area paper chart. In the year 2017 there are numerous cheap ways of acquiring a GPS/GNSS fix. A single point failure or even a full electrical failure should not throw you back to the Stone Age. 

Celestial navigation by sextant absolutely has a place in the modern world. It provides that "cross-check" that helps navigators maintain situational awareness, and it can detect spoofing on a coarse scale, if no other non-GPS options are available. And for the small boat navigator, maybe best of all it preserves the electronics and power for those circumstances when they are most valuable. Don't just see it as the sole "emergency" solution when the main electronics fail. ...that's 1990s thinking! :)

Frank Reed