Baby Cody was actually played by two sets of twin boys.
The boat slips and bar scene were filmed at Dockers Restaurant & Marina in Dania Beach, Florida. The boat's name ("My Escape") was applied by the show's scenic department.
The crime scene/search and rescue area was actually various areas of Flamingo Gardens, a south Florida plant and nursery that's been around since the 1930s.
The fireflies used in the scene where the girls were outside trying to capture the insects in jars, were added during post-production using a CGI (computer graphic imaging) method.