This feat exists simply to add the supplementary information provided in Chapter 2 of Xanathar's Guide to Everything to a character's sheet so that they can more easily flavor their interactions with their tool proficiencies. It does not function as a standard feat, and is not to be taken as part of an Ability Score Increase.

Proficiency with navigator’s tools helps you determine a true course based on observing the stars. It also grants you insight into charts and maps while developing your sense of direction.

Components. Navigator’s tools include a sextant, a compass, calipers, a ruler, parchment, ink, and a quill.

Survival. Knowledge of navigator’s tools helps you avoid becoming lost and also grants you insight into the most likely location for roads and settlements.

Sighting. By taking careful measurements, you can determine your position on a nautical chart and the time of day.