Starlink can do half a gigabit per beam and point 8 beams at the same cell.
With 5000 people on a ship, that's enough bandwidth for half of them to watch HD video at the same time.
On land they want to spread out the bandwidth as much as possible, but on the ocean most cells are empty or only need a time share fraction of a beam, so they might as well focus on those mini cities.
> Starlink can...point 8 beams at the same cell
Source for this capability?
https://mikepuchol.com/modeling-starlink-capacity-843b2387f5...
Beams are 250MHz wide and they have 2GHz of allocation.
I don't think a single satellite can saturate a cell, but I think you're right on a couple gateways being able to soak up a couple beams from multiple birds. That might work on rare trans-oceanic cruises. But for the most-common routes, which nose along coastlines, there are other beam uses.