The Navigator Passed the Goal Without Seeing It

Vision-language navigation policies often know enough to explore but still fail at the final recognition step. The StopWatch analysis identifies explicit goal grounding—detecting that the object is in view and estimating its distance—as the dominant missing capability. Adding that grounding improved results across six benchmarks and three scene collections. On corrected benchmark annotations, a policy given ground-truth grounding nearly matched the expert that generated its demonstrations, leaving much of the remaining headroom in perception rather than navigation policy learning. These are benchmark findings, but they redirect attention from ever-larger action policies toward the simpler question of whether the robot knows it has arrived.