Port Cities.

[ColdWizard]

Don't know if it's known info or not, but I can't find it in my searches, so here's a bit of info I gleaned.

A city will be a port city (able to build ships and whatnot) if it:
Is adjacent to a body of water of 9 or more ocean squares or;
Is immediately adjacent to 2 or more ocean squares.

So a lake of 2 ocean squares can't be used if you build on one end of the lake, but can be used if you build on the side. You can also connect two (or more) 1 square lakes with a city and it will be a port.

[Bloody Monk]

(able to build ships and whatnot)

Depends on what you mean by "whatnot".

A city by a one tile lake can build a Harbor.

Which makes for one of the quirks about Civ2, that you can have a Harbor in a city that can't build ships.

Monk

[ColdWizard]

Everything port related except for harbor and offshore platform. Which may only be port facility, I don't recall.

[Father Beast]

Depends on what you mean by "whatnot".

A city by a one tile lake can build a Harbor.

Which makes for one of the quirks about Civ2, that you can have a Harbor in a city that can't build ships.

Monk

err... not exactly. it would be more accurate to say that you can build a Harbor in a city that can't build any ships you can use.

if your city is diagonal to a one square lake, you could float a battleship in there if you wanted. wouldn't do much good, but there you are. I've seen the AI do it.

[ColdWizard]

AI cheats. I haven't been able to reproduce that unless the city also connected to another body of water.

[Father Beast]

Gee, Coldwizard, you're right.

I loaded up one of my ics games and there seems to be three different states:

cities with no ocean access cannot build ships or harbors.

cities with access to a one square lake can build harbor and offshore platform, but no ships or ports or coastal forts.

cities with access to the real ocean can build ships, coastal fortresses, port facilities, harbors, and offshore platforms.

cities with access to 2 square lakes were varied.

A city set like this:

LLL
LWL
LWC
LLL

had full production.

But, a city set like this:

LLL
LWL
LWL
LCL

Had limited production.

This fits the description you gave, but I would have to do more extensive testing with the map editor to see for sure just what the limits are.

Or I could take your word for it....

[ColdWizard]

I tested it with various lake sizes and configurations, often with multiple cities on the same lake. When I got different results on the same lake I investigated further and found it as I reported it. I tweaked 3 different maps with various lakes, but may have missed some. The results I got were consistent though.

Editing the map with the cheat menu didn't seem to match the results as I ended up with a lake greater than 9 squares (I think, but am not sure) where new cities were not ports. It could be only original sizes are considered, but I tweaked my map instead of pursuing it further.

[N35t0r]

I'd guess that this last behaviour is tied to the landmass number, which is only assigned on game start, so changes with the cheat menu won't affect it.. IIRC, there's only up to 63 distinctive landmass numbers each for land and ocean.

All small lakes are grouped into the 63rd sea landmass number, so I'm guessing that a city bordering one of these will be unable to build ships. (Although this only seems to be if it borders just ONE ocean tile, according to what you describe)

These two kinds of coastal cities is well known, at least in the scenario community (Gothmog's city editor can be used to set/remove these flags to specific cities, and had been used in countless scenarios).