The prospect of death is bad enough. But for some people – scuba divers, fishing enthusiasts, retired Navy sailors – what’s really chilling is the idea of spending eternity on land. One alternative: burial at sea in an artificial reef. An Atlanta company, Eternal Reefs Inc., takes cremated remains, mixes them with concrete and forms them into balls that resemble igloos with holes. Designed to last 500 years, they support marine life by providing hiding places for fish and offering hard surfaces for sponges, coral and other marine creatures.