Rank 1: Living creatures and harvestable wasteland plants that come into view are now highlighted (can be toggled). You also harvest double from wasteland plants.
Rank 2: Can build a cooking fire and bed roll anywhere. (sleeping in bed roll grants 5% XP ‘rested perk’ gain for a short time).
Rank 3: You can now craft two cooked items together into a meal for an added bonus. (Meals would be a new list item in the cooking menu)
Rank 4(rank 40): Invisible enemies are now highlighted.
Rank 5 (rank 50): All map locations are revealed but those not discovered cannot be fast traveled to.