WAAS Enabled vs. Disabled

[Turtle]

Last year I was Elk hunting and had my Garmin Vista with me.  I was heading into a meadow, about 2.5 miles in.  I had loaded the meadows coordinates into the GPS thru some Topo Software before heading out.

Once in the field, it was thick dark timber the whole way and the unit was unable to receive satellite signals.  Along the way, I found several small openings in the trees, but apparently the openings weren't large enough for the unit to receive satellite signals.  I ended up turning the unit off and continuing on with my compass and found the meadow that way.

That night back at my camp, a friend stopped by and suggested I turn OFF the WAAS feature and that would help the GPS in thick timber.

I ended up getting my elk the next day and headed home.  I didn't take the time to see if turning the WAAS feature OFF did indeed help the unit or not.

Does anyone know if turning the WAAS feature OFF helps the unit receive satellite signals in thick timber?

[daddywpb]

I have noticed that the WAAS feature does affect the accuracy of my Legend. I turned it off a long time ago, and the reception seems to be better. Could just be me though.

[Siskiyou]

The WAAS satellite system is incomplete.  There are currently two WAAS satellites.  Basically an East Coaster and a West Coaster.  The WAAS system is for aircraft navigation.  The coverage for land navigation is poor in most mountain zones.   I have three gps units, one is a fishfinder/Gps, and two hand held ones.  On occasion I will enable the WAAS function on a gps.  I have successfully received a WASS signal in the long open Central Valley of California, but lose it when I get into the hills.

The DISADVANTAGE:  When you are in a non-WAAS reception area your gps unit continues to search for a WAAS signal.  The searching decrease battery life.  Most recommendations are to disable the WAAS function.

I have had the same signal lost with my Garmin Legend in tall black timber.  When I step back out into an old clearcut unit I will start receiving the signal again.  I want to try the new 76C in this same stand of timber.

During the last two months I have put about two hours a day on my gps units while out walking.  A friend who an earlier model Garmin Gps72 also goes along.  I will have either a Garmin Legend or a Garmin GPSMap76C.  Both the Gps72 and the 76C can be setup to sound a tone when satellite contact is lost.  I have noticed the friends Gps72 seems to lose the signal often when we are in timber.  Garmin has undated the 76C operating system which maybe why it has better reception.  The reception of the 76C is better then the Legend.  At this point I cannot give a percentage of improvement.  I believe part of the problem maybe the way my friend manages his batteries.  While he uses alkaline batteries, he normally does not have fresh batteries in his gps.  The last time out he had some old batteries he had pulled out of a flashlight and they gave up in a couple of hours.

When standing on a ridge top with the 72, 76C, and the Legend operating out in the clear all three seem to receive the same number of Satellites.  The signal bars of the 76C  indicate that it's reception is stronger.  At this location I was receiving 8 satellites, none of which were a WASS satellite.  I believe that I had the WAAS function enabled.  About a mile to the West there was a higher ridge top that could have been blocking the signal from the low flying WAAS satellite.