The two-way messaging is a real plus, and so is a system you see working every day that can also call for help
Hands on with Ben Ellison as an “Armchair Transatlantic”
InReach
DeLorme inReach Gets Weather & Goes To Cuba (BLOG)
I've long felt that the DeLorme inReach is a valuable safety and communications tool for boats that sometimes go beyond reliable cellular (and/or VHF) contact with friends, families and rescue centers.