There was a bridge across the stream too, a short distance below.

The boys were a little inclined to be afraid to embark, in what appeared to be a rather dangerous navigation, but they had confidence in Forester, and so they readily obeyed when Forester ordered the crew aboard.
"Now, Mr.Bowman," said Forester, "keep a sharp lookout ahead for rocks and snags, and fend off well when there is any danger." So Marco kneeled upon a small seat at the bow of the boat, and looked into the water before him, while Forester propelled and guided the boat with his paddle.

They advanced slowly and by a very tortuous course, so as to avoid the rocks and shallows, and at length, just above the bridge, they came to a wider and smoother passage of water: and here Forester ordered the oars out.

There was only room for them to take four or five strokes before they came to the bridge, and under the bridge there was only a very narrow passage where they could go through.

This passage was between one of the piers and a gravel bed.