When WAAS satellites are moved around in their geosynchronous orbits they sometimes drop below the practical treeless horizon and you lose them till another is moved into place. When WAAS was first set up there was one that covered the east coast of the US pretty well but it was moved out over the Atlantic somewhere and is almost never available for ground-users anymore. It's not intended for ground-based users anyway. An aircraft using WAAS can see the satellite almost all the way to the horizon where ground-based mobile users typically need it to be 20-30 degrees above the horizon for reliable capture.
BTW, you cannot update the GPS software/firmware unless the manufacturer makes an update available for download. Since the entire automotive GPS division of Lowrance is defunct, you probably will not get any future updates at all, unfortunately.
WAAS is highly overrated in an automotive GPS. The GPS has "stick to roads" permanently enabled and cannot benefit from WAAS to improve accuracy. Even with WAAS, the validity of its correction decreases as you get further away from the ground-station on which it's based. It's intended for higher precision aircraft navigation near airports when aircraft GPS systems need it for accurate altitude and glide-slope location till in range of the actual airport navaids. We just happen to be able to utilize its corrections when available for slightly improved accuracy we can't use anyway. CEP for most modern GPS devices is down to 10 meters 95% of the time anyway. How much more accuracy do you need?
Bob Peloquin - Moderator-Lowrance iWay forum Massachusetts, USA Various Iways, nüvi 750