Hi, Nancy. I don't know where I heard or read the following information
- could even have been on this list - (if so apologize for the repeat)
but I remember the message and
it was recent:  That it is important to be careful when pulling off the
side of the road by yourself in the Keys and leaving your car unobserved -
that there have been incidents of breaking in and taking things by
persons who are waiting for such opporutnity.

I hardly want to put the kibosh on fun collecting in the Keys.  I myself have done  the very same thing, stopping by
the sides and wading in non-restricted area (although not recently)
.
There were all kinds of shells to be found,latirus, bivalves, cones,
astraea. Have
a safe and productive trip and let us know what you  find.
Karen