All FloatHub Cellular units come with an onboard SIM card that provides for worldwide cellular network connectivity. In an effort to keep billing and account management as simple as possible, we cover all reasonable cellular data costs as long as you have an Enhanced Monitoring Plan. These plans cost $9.99/month (or $99.99/year), and users that have a FloatHub Cellular device get up to 5 MB of cellular data included for free each month.
This 5 MB limit is generally more than enough to cover mixed WiFi/cellular coverage. If you are in a scenario where you want to use 100% cellular and have a lot of traffic (boat frequently used, lots of sensors, AIS relaying over cellular, etc.), you can have it cut out at any data limit you like and pay $0.50 per MB for as much as you actually use up to that limit (over the free 5 MB). Data usage is unlikely to exceed 10 MB or so in most scenarios, but the sky is the limit on AIS relaying in busy waterways. Note that there is an option to only relay AIS over WiFi and just use cellular for regular onboard monitoring data (this is the factory default).
If you want to opt for a higher data limit, you can do so on your account page (note that only users of FloatHub cellular units will see this option):
Please note that if you'd only really benefit from cellular connectivity during certain months of the year, you can turn on Enhanced Monitoring for only those months where you want cellular coverage. Your device should automatically reconnect to the cellular network within an hour of you turning back on Enhanced Monitoring via your account on the FloatHub website. And your device will continue to relay data over WiFi during the months where you have only basic (i.e. free) monitoring.
As always, please let us know if you have any questions.