Zak & Lynn,
 
Welcome to Conch-L.  You certainly picked the two most popular families
to concentrate on.  You should find plenty on the list who share your
enthusiasm for those families as well as some who will gladly work a
trade or two for shells from your diving area.  This list has been going
for quite a while (thanks to the  sponsorship of Conchologists of
America) and has greatly increased my interest in and knowledge of
shells.  Hope you enjoy yourselves, there are lots of great folks here,
and a couple cranky ones, but that just adds to the interest and flavor
of the place.
 
Again welcome,
 
Tom Eichhorst in New Mexico, USA