Student or Learner
I will assume that the booked berth relates to passenger ships where a person could book a berth. This meant that they had their name in the book and had a certain berth or place to sleep on the ship. Those who had not booked their berth took their chances.
What does `took their chances' mean in this paragraph?
Please explain it.
They turned up at the dock and hoped they would be able to find a berth.