20 Dollars - Elizabeth II Poseidon

The Poseidon coin is part of Cook Islands' long-running collaboration with the European Mint and various private distributors who have used the territory's licensing agreements to produce high-relief collector pieces with little connection to actual Fijian — or in this case Cook Islands — monetary policy. Cook Islands has issued coins under Elizabeth II's authority since 1972, but the majority of its modern numismatic output is contracted abroad and never circulates domestically.

At 93.3 grams, the flan would have required multiple die strikes to achieve full depth in the relief — a standard production approach for this class of privately contracted sovereign issue.