What works for us:
Netgear Unite Explore hotspot. Originally built/marketed for AT&T, but purchased ours unlocked off Amazon. Have successfully used T-mobile,
Google FI, and AT&T SIM cards in this unit.
Netgear 6000450 MIMO Antenna. Directional, suction cup mounted to inside
cabin window. Probably use the hotspot
without this
antenna about 90% of the time. The other 10% of the time, in very
remote areas or
offshore (up to 8-10 miles) it helps pick up a data connection when we otherwise might not have one.
This is our primary connection. We've been using what I call "gray market" AT&T
service,
sold on ebay by various sellers for about $100-$110/month (look for "rural internet" or "RV internet"). This is truly unlimited, no throttle
service. I suspect some of these resellers are abusing the terms of some corporate plan (their problem, not mine), and your line can be cancelled if AT&T clamps down on them. This has happened to us twice, both times at the end of our plan month (with some advance warning that it wouldn't renew). This is a hassle, because you have to order a new SIM and find someplace to have it delivered (not too hard on the east coast), but we've always gotten the full month of service that we paid for.
For backup...
2 iPhones on Consumer Cellular. Dirt
cheap service, but can be "expanded" on a month-by-month basis to their Unlimited tier, which allows high-speed tethering up to 35 gigs/month. CC primarily rides on the T-mobile network, but they'll send you an AT&T SIM if you request it. Ours ride on AT&T (we requested because TMO used to be terrible near our home in TX), but if you want to use international roaming with CC you need to be on the T-mobile network.
1 Android phone and 2 tablets all on the same Google Fi Unlimited Plus plan. Mostly rides on the T-mobile network. Can hotspot via the
phone, but it throttles severely after 22 GB. Despite the low data cap, Google Fi has two big advantages. First, you can request as many data-only SIMS as you like at no cost. This allows us to pay for only 1 line (the phone), but have 4 SIMS (phone, 2 tablets, and Netgear hotspot). All 4 devices share the same data pool, but we don't actually use much of the Google data because the 2 tablets connect via
wifi through the above hotspot whenever we're onboard, and we only use the phone and hotspot SIM as backup. And second, you get free high-speed data in most international locations. There are caveats to this (have heard conflicting reports - Google may cancel the line if you use it heavily outside the US for several consecutive months), but it's worked for us in
Canada,
Antigua,
Guadeloupe and
Dominica.
Note that the two "backup" tiers above are just what we already had when we were living on land, and were a fairly
cheap way to serve two phones and two tablets (with ATT/TMO redundancy and international flexibility). So the only thing we actually added when we moved aboard is the Netgear hotspot and it's grey-market plan. But with this combo, we've never felt the need to add a cell booster,
wifi booster, antenna up the
mast, etc. One of the above -- nearly always the Netgear hotspot riding on AT&T -- has always just worked up and down the
east coast.