This 49-foot trawler from 2003 was docked in Annapolis, Md., and initially priced at $380,000 — too much. When the price fell to $335,000, Mr. Calder decided to take a look.

With a 40-foot yacht, the rate falls under the 35.1-60 ft category, which costs $9.50 per foot per night. So, for two nights, the cost would be $760, or $380 per night. For comparison, let's take ...