More than 90% of my tracking messages get through when flying in Southern UT or anywhere else in the lower 48.
I keep my SPOT on a little non slip bean bag holder as far forward as it will fit on the glare shield. By putting it forward as little as possible of the airplane roof will block its view of the satellites. The non slip bean bag keeps the SPOT from sliding around.
The SPOT antenna is located under the SPOT logo on the device and needs to be pointed towards the sky. If it is upside down (logo facing the ground) you will not get nearly as many successful transmissions. Even having the SPOT horizontal will eliminate about half of the available satellites.
The image below shows a sample snap shot of the location of the SPOT satellites and their coverage area. Southern Utah is being covered by 4 satellites in this image. It looks like all of the lower 48 states have 2-4 satellites in view. Northern Alaska only has one. The satellite covering Northern Alaska is down south by the Aleutian Islands and so a view of the southern sky would be required. In Utah there is a satellite with in view in every direction so at this particular time a SPOT beacon pointed in any direction should successfully transmit to a satellite.
The satellites are always moving and the image above is just an example of where they were at one point in time. The above image might make you think that SPOT should work in the middle of the Pacific Ocean which it does not (see the coverage map below). To successfully pass a signal the satellite has to be able to see your beacon and one of the SPOT ground stations at the same time. SPOT does not work in the middle of the ocean or in southern Africa because there are no ground stations there. I'll try to get a map of the ground station locations but do not have one available at the moment.
I'd be glad to try to answer any other SPOT questions you may have. As always, BCP members get a 10% discount on SPOTs and everything else at
Prepared Pilot by using the coupon code "BCP"