"Maritime" Cellular Network
 

I was on the US/Canadian border and the Detroit river today and did a manual network scan and in addition to the US networks (ATT/TMobile) and the Canadian ones (Rogers/Bell/Telus/Wind), I saw one called "Maritime." Has anyone heard of that or know what it is?

I googled '"Maritime" Cellular Network' and some interesting things came up.
I don't dare make a guess if any were relevant to your question because I most surely will be wrong. Perhaps you can look and see if any make sense?

Would it be possible to get the MNC? Does anything like a cruse ship make it that far inland? Thinking maybe someone left a shipboard GSM system active when they shouldn't have?

In the south of France last year, in some narrow valley on the way up to a higher wider one, there was a network name which was none of the main ones, just something generic sounding, though now I can't remember what it was.

I wondered if all the networks had jointly arranged the coverage and all had roaming on it, but there could be some other explanation. But my phone had automatically connected to it.

Can this network you've found be similar? Would your phone register on it?

I remember when someone reported that they could pick up a Swedish 900 or 1800 network in a very localized area of Silicon Valley. Turned out that the Ericsson research lab was in that block. The engineers had set up a "test" microcell inside the building that really was mostly to allow them to make and receive wireless calls at domestic Swedish rates.