What is the correct ruling in this debate?
This answer made most sense to me:
Patrick Jamet wrote:
I repeat : To build a port at a location with an industry card, you need one of these:
• a counter at this location,
• (or) a rail to this location,
• or a ship linked to this location.
It doesn't matter if you have a port at the opposite of the map.
By “a ship linked to this location”, I mean : your ship — ONE link (not a string of 24 links made of 23 other players' ships and one of yours lost somewhere in the middle) — the location.
Also the Martin Wallace answer supports it:
Martin Wallace wrote:
The wording in the rules should ahve been a little tighter. A sea lane has the potential to be a rail link for any player, but only if they have a counter at one end. You cannot use it to build from using an industry card if you do not have one of your counters at one of the two ends (one of these counters could be a rail link).
Hope that helps.