Mapless is a synonym of chartless.
As adjectives the difference between mapless and chartless
is that mapless
is without a map or maps while chartless
is without a chart or charts.
Without a map or maps.
* 1955 , John Stewart Collis, The Moving Waters (page 86)
- It had seemed that the earth now offered nothing further to explorers; that the virgin forest, the untrodden desert, the mapless mountain, the unjourneyed sea were all things of the past
Without a chart or charts.
Not mapped; uncharted; vague.