A review of anchorages, and the kinds of ships that use them most on the Columbia

Today, I thought we could do an overview of anchorages on the river.  We see ships in anchorages up and down the river corridor. Why do ships stop there? What happens on board ships in the anchorage? Can ships just anchor anywhere? Why do some this anchor and others don't?

We'll talk about all this and more in today's show.