Carried a Sat ph in Afg my second to last deployment. Dont help much when yer blowed up or batteries go dead.
I learned long ago hunting men in the jungle. Never trust anything that takes a battery or goes to sleep. Trip wired claymores and trip flares do neither.
Also, a very good plan usually never survives first enemy contact. Which here is Shelter, water, food, fire.
There is no second place in Survival! You just do or dont.
H