Morning
Confirm weather and hours. Local Clyde time is always a valid choice.
Afternoon arc
Glasgow, Loch Lomond, or Culzean — not all three.
Return
The ship waits in Greenock. Late Glasgow dinners are a fantasy for day callers.
One day
One day from Greenock
Orient at the terminal, pick a single outbound theme if leaving town, and reverse to Greenock with margin.
Check the Clyde maths
Use the planner and enquire if Culzean distance worries you.