Source : Webster's Revised Unabridged Dictionary (1913)

Chartless \Chart"less\, a.
   1. Without a chart; having no guide.

   2. Not mapped; uncharted; vague. --Barlow.

Source : WordNet®

chartless
     adj : (of unknown regions) not yet surveyed or investigated;
           "uncharted seas" [syn: {uncharted}, {unmapped}]