This is the first time that I got to read a Dana Girls Mystery. We read a lot of Nancy Drew, Hardy Boys and Three Investigators mysteries in our middle school years, but never chanced upon any Dana Girls mysteries.
I did not find anything remarkable or even interesting about this mystery. The girls are alternately going to the town or the lighthouse in the name of investigating the mystery. The whole thing was predictable. Could be because I ought to have read it 40 years ago.