Or that you're in a location where GPS reception is difficult, like a city core, like eLoran proponents would likely remind you. Unfortunately, I think the ship

Or that you're in a location where GPS reception is difficult, like a city core, like eLoran proponents would likely remind you. Unfortunately, I think the ship sailed when the US decided to decommission its chain. Another weakness of Loran is that it's only available near the coasts (where precise navigation is a necessity for ships), so it won't help you in the middle of the ocean or in Las Vegas.