Tyson is correct in the one-way operation of Outernet.
That said, I have used my Lantern terminal on large cruise ships and small yachts successfully with this caveat: The patch antenna has a 40 degree beam width which means if you operate at higher latitudes (say 20 degrees or higher), you just can't lay the antenna down pointed at the sky and receive. You would have to tilt and point the antenna.
If you are on more or less a straight passage, you can leave it unattended once set up, but on smaller ships the herky jerky motion of the ship might cause you problems.
I had no issues on a recent Panama Canal passage on Oceania's Regatta at latitudes less than 10 degrees.
By the way, the recently added news and weather content (even though one-way) are very impressive and useful. Ken