Hi, thanks for your feedback.
Can you please provide the place where the ferry routes are missing?
I can see ferry routes both on Basic and Outdoor map.

Ah, it looks like they are actually there, but only at a very close zoom level -- making them not very useful. For example, compare the following views of the Irish Sea:

...or around the island of Tsushima, Japan:

Issue of maptiler and openmaptiles data. Ferry routes are not included in transportation layer for zoom 10 and lower.

Mapnik renders ferry routes starting zoom 8.

I will try to address this : )

@kudlav was right, I misunderstood.

The data doesn't exist at larger zoom levels, it's not a styling issue.

Ferry routes visibility at lower zoom levels was improved in OpenMapTiles 3.15

https://www.maptiler.com/news/2024/04/openstreetmap-data-prepared-for-advanced-cartography/

Should be fixed now. They are visible starting zoom level 4.

Thanks for the screenshots @kudlav 👍