You don't need that stuff. Get a piece of string, mark it at 9 mile intervals for 120 times (thats 2 hours for the digital watches) and place it at the start airfield. Move the string anywhere on the map, as long as the 120th minute is at the end landing point (even if it comes back to the start point) , you can go there. Flight planning should take about 10 minutes this way - about as long as it takes to boot up and log into modern planning software....
Keep the string in flying suit, and maybe a spare or another one for a different scale. Use indelible markers on the string so the flying suit can be washed without losing your planning aid.
in extremus, it can be used in-flight too.
Costs about 83 cents for the string and a buck for the marker. I believe you can claim it on tax too. Most news-agencies sell them.
For those who can't fly at 540 knots at low level for 2 hours non stop, invent another method.
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