-- coverage is literally perfect for anywhere I take my (imaginary) yacht! - south of france? check! italian riviera? check! miami? Check! LA? Check! $5k a month? In YachtLand $5/mth is pocket change --
And for us actual realistic ones - a lot of anchorages around Europe have pretty decent LTE to work with. You won't be able to work while on passage anyway.
We did a month of boat touring around Italy/ex-Yugoslavia last year and mobile coverage in anchorages is very much hit or miss. Generally ok for browsing but video calls worked ok may be 30% time. Essentially you can't count that you can take work call and have decent experience. Huge inconvenience. I had a few "can't miss" calls and essentially I had to get to city 1-2 hours beforehand and then look for hotel/coffeeshop with decent wifi .