So if you cross the Atlantic you should be able to have connection to ground station for most but the middle third of the journey, which is still covered, just not that extensively. Most are equatorial though. It's really the Polar regions that must have laser comms but besides a few maniacs like Erik Aanderaa it's not needed by many sailors.

BTW T-Mobile needs Starlink V2 sats. They don't fit on Falcon 9 or Heavy, they need Starship (the largest man made flying object that exploded last Wednesday).

And also the V2's have proper intersatellite optical coms, which is crucial for bandwidth far from ground station, such as the ocean or deserts or polar regions or very rural areas etc…

The Maritime service is aimed at high end users on multimillion dollar motoryachts like you say. And cruise ships too. It's likely the small boats will remain with the RV's under the new Roaming thing. Don't ask me how that'll work, its all very much in flux, though they are aware of the customer base and also that most boaters will not be buying the official maritime version due to cost. So we shall see. I believe it should keep working normally, but no promises from me, I'm familiar with the hardware, nothing else.

Also keep in mind this is very new and SpaceX is expecting at least another 20 billion in expenditure for the full phase 1 constellation. So your paying first adopter premiums right now. Of the phase 1 constellation so far only 20% of satellites are on orbit. So the system is at 1/5 capacity only, technically not operational but in testing. They honestly don't care that much about low budget boaters right now, it costs them a lot to offer bandwidth of shore compared to on shore. At least within the range of ground stations, which is still 100+ km. So you can be that far off shore and still be talking to ground stations via just one satellite. Especially the older sats up at 500 km. They got a fair bit of reach.