Both Megan and Nancy Bovy sent me this one.
The Neptune Memorial Reef is located in open waters 3 1/4 miles off the coast of Key Biscayne, which means any certified diver can visit. The artificial reef's first phase allows for about 850 remains.This makes Long Cemetery #2 seem downright accessible.
The ashes are mixed with cement designed for underwater use and fitted into a mold, which a diver then places and secures into the reef. A copper and bronze plaque is installed with the person's name, date of birth and death. There is also a line for a message. [Link]