I've been nearly 30nm off-track after going nine hours without an update across the Pacific. There was a pretty big heading change when we finally got a couple of DME's off LA.
Hey 18 wheeler, the Fork Tail Doc may have few spare GPS units that'll fix that problem for ya!
And on that regard. 30nm off after some 4000nm....not bad shootin, pard
EDIT TO ADD- in the same comparison, if 18wheeler was piloting said carrier they would be less than 2000ft off course for a similar error.