Each one is a real island grown from its own number: beaches, hills, forests, and a mountain with a grotto and caves to explore inside it; the larger ones also have a lagoon. Its holder builds on it block by block. You arrive above it, then walk in from a link, with no wallet and nothing to install, and you meet whoever else is there. Challenges, events and a shop are its holder's to run. Everything a port holds belongs to the island, so it stays with the island if the island changes hands.
How a port is made: forge an island from ten yachts (Islands), wake it, then walk into its port and build. Its grade is its size: a Cay is 80 blocks across, an Isle 96, an Estate 128, a Flagship 160. Building is free. A port is public or private: a private one opens with its holder's code, to the holders of one NFT collection, or with a pass from its shop. Its holder chooses who builds beside them. Nothing in a port earns Anchor Points, and the club never holds a port's money: a shop is paid straight into the island's own account.