Satcom is indeed still key. A ship may be nearby, but a ship's mast is only so tall. Assuming a typical cruising altitude of the aircraft at 10km, and a mast h

Satcom is indeed still key. A ship may be nearby, but a ship's mast is only so tall. Assuming a typical cruising altitude of the aircraft at 10km, and a mast height of 100m (generous), the line of sight radio horizon is 30km. A friendly AWACS gives you about 400km. Even with satcom, jamming of these links remains a very real concern. GEO coms sats by their nature have a relatively low power signal. Clever modulation can do a lot, but it can't escape the fundamental physics.