The Bridges & Ports Add-on for Cities: Skylines II has 6 achievements.
Gather 10 000 tons of Fish resource by fishing boats or fish farms in one city.
Transfer 24 000 tons of resources through Cargo Ports.
Gather 2 000 tons of Oil with the offshore oil platforms in one city.
Build 5 Draw- or Lift Bridges in one city.
Build 5 kilometers of Quays in one city.
Build 2 kilometers of Piers in one city.