The point made by the original poster was that if you can identify
three points you still don't necessarily know your true position.

REF FER ENCE points, gene. for the krimminy sakes, gene. ya gotta have
REFERENCE points. And you no gots dem when you only gots speed through the
water and a compass and a timepiece.

In the discussion of the efficacy of ded reckoning

efficacy (sic) is the wrong word. effectiveness is the right word, and DR is
effective as no more than a guess of deteriorating accuracry as time goes on.

if I am not lost, then I am not lost?

but you ARE lost if you don't have **reference** points to **refer** to,