NavList:

In looking at http://www.bbc.com/news/world-us-canada-41772323, the picture of the boat suggests that they had an intact mainsail, and I think I am seeing a furled headsail on that forestay.

I don't want to say "navigational failure" as a simple reflex on my part, but it sure looks to me like they had all the propulsion they needed to go anywhere in the world...provided they could figure out where they were and knew how to use those sails. 

It looks for all the world like they were depending 100% on a chartplotter for navigation, and when it went down they had no backup GPSes, and perhaps not even paper charts.  All they could see was a vast ocean surrounding them on every side.  When they looked up at the stars at night, it didn't even flicker across their minds that these stars might be navigational resources.

The Atlantic is such a small ocean, all you need to do is figure out the difference between sunrise and sunset and head for the nearest continent.  The Pacific is large enough, however, that if you miss the island you are aiming for - in this case, Tahiti - then you have a problem.

If I had to grade them, based on the hints we have from these articles, I would give them:

• Carrying multiple GPS units in ziplock bags in case the main chartplotter went down = F
• Carrying an EPIRB = F
• Carrying paper charts on board = F
• Carrying a sextant on board = F
• Stocking the boat with a desalinator unit plus food for a year even though they only planned a voyage of a few weeks = A+

If they indeed had an intact main and headsail, and still felt they had a "propulsion failure" then I would also give them an F for failing to take at least a beginner's dinghy-sailing course before striking off across the Pacific Ocean in a sailboat.

And honestly, I'm pretty sure that any member of this group could manage to hit Australia even without a sextant.  But I will give them:

• Pure, dumb luck = A+

Bob