Then I had a sudden thought, and hunted up all the steamer sailings. There was no boat which left for the Continent at 10.17 p.m.
Why was high tide so important? If it was a harbour it must be some little place where the tide mattered,or else it was a heavy-draught boat. But there was no regular steamer sailing at that hour, and somehow I didn't think they would travel by a big boat from a regular harbour. So it must be some little harbour where the tide was important, or perhaps no harbour at all.