If a terrestrial burial sounds unappealing, there is a way to spend eternity caught between the devil and the deep blue sea. Eternal Reefs of suburban Atlanta will take your cremains, mix them with concrete, and mold the melange into "reef balls," which are planted underwater as habitats for ocean coral, sponges, and fish.

While cremation is increasingly popular (modern mobility has rendered the family plot passe), most who opt for urns become what Eternal Reefs founder Don Brawley calls "shelf people"--their ashes relegated to a mantel or closet. To avoid that fate, four years ago Brawley's ailing father-in-law hatched the idea of having his remains added to a reef ball in order to "be part of all the life and excitement down there."

These days customers can choose from three varieties of igloo-shaped reef balls: the Atlantis (two tons, $3,200) or the Aquarius (400 pounds, $1,500), or, for $850, ashes can be mixed with others to create a "community reef." (Cremation not included.) As for Fido, you can be buried with him in an individual reef ball (he'll cost extra), and Brawley may eventually offer a pet-only communal reef.

The igloos, designed to last 500 years and withstand hurricanes, are then donated to reef-restoration programs. Each bears a memorial plaque, and families are provided with latitude and longitude data in case they want to drop down for a visit. To date, Eternal Reefs has placed more than 100 memorial reefs in waters off such popular resort communities as Charleston, S.C.; Fort Lauderdale; and Sarasota, Fla. Brawley is now eyeing California shores. It makes an enticing tourism pitch, he says: "Beautiful beaches, good fishing, and Grandpa."