To turn off WAAS on Magellan receivers try the following:
From any screen press MENU
Press right arrow, left arrow, right arrow, left arrow in sequence (you may have to do this a couple of times)
A box with 00 in it appears. Use the up arrow key to change the "00" to a "03" and then press ENTER.
A few boxes should pop up. Press ENTER to turn a "ON" to an "OFF" (all boxes will change simultaneously).
Press ESC twice.
Turn off the unit. Then, when you turn it back on the WAAS satellites should not be visible in the satellite screen (W's). Note that the boot screen will still say "WAAS."