Historical clue formulations

• Annular reefs — 2026-09-05
• Bikini and others — 2026-07-20
• Islands that form atop underwater volcanoes — 2023-01-08
• Spots for snorkeling — 2022-09-11
• Key rings? — 2021-08-21
• Coral rings — 2020-02-18
• Ring-shaped islands — 2019-01-22
• Islands surrounding lagoons — 2017-12-26
• Much of Micronesia — 2011-09-24
• Coral islands — 2011-01-05
• Snorkeling sites — 2009-08-16
• Ocean rings — 2008-01-31
• Many of the Marshall Islands — 2005-12-04
• Lagoons' surroundings — 2005-11-07
• A lot of Oceania — 2004-04-09
• A lot of Polynesia — 2001-07-01
• The Maldives, e.g. — 2001-06-16
• Many of the Marshall Islands — 1998-11-09
• Key rings? — 1998-06-21
• The Marshall Islands, e.g. — 1998-05-25
• A lot of Micronesia — 1996-08-04
• Part of the Ralik Chain — 1994-01-15