Interesting point Emilio, you wrote
" Where is the offshore Strombus habitat?  I thought Strombus were grazers
only where the Turtle grass grows, not on the patch reefs or sandy areas
between the shallows near the mainland and the main reef line."
 
What I've experienced , Strombus seem to like turtle and eels grass flats
between 3-10 ft but not limited to this habitat as most strombus are poor
readers thusly they don't stay in the habitat prescribed in the books.
One other small snippet to mention it seems strombus are found  in clumps or
herds that are on the move from one area to another. Usually when you find
one you'll find more close by.
just my observations.
 
Thanks, Mark James & Peta Susan Bethke
3001 South Ocean Dr. Suite 4-V
Hollywood, Florida
33019-2804
U.S.A.