Rose put an arm round his shoulders to hold him still, and sighed. ‘Mrs Jones was right about that. I think if Bella had gone on longer she could have toppled a house.’ She shook her head disgustedly. ‘And not a hair out of place, look at her! How did she find the one clean spot in the harbour to lie in?’
Here the people are on a harbour. But I couldn't understand what did the writer want to mean here by saying "the one clean spot in the harbour to lie in". Can you help please?
It's hard to say without more context, but I assume that the others are not as clean and well-groomed as she is and the harbour's dirty.