Global two-way communication
Depending on where you travel, you may not be within range for VHF (line of sight limited to about 5 to 10 miles) or cellular networks. A properly installed marine single sideband transceiver is an expensive option, but it may not be the best solution for every vessel.
The least expensive way to add two-way global communication to insure you can get the right help you need in an emergency is to buy the Garmin inReach SE+. With this device, you can request help/rescue, specify exactly what you need, and receive confirmation on what and when it will arrive. You can also receive 7 day marine weather forecasts.
The next step up is the Iridium GO! satellite Wi-Fi hotspot. The cost as of Mar 2018 was about $1200 for the equipment with the external antenna, plus $125/month unlimited data. Note that the data speeds will be slow in comparison to most cellular networks, but you will have global communication capability.
