The Cook Islands, a sovereign state in free association with New Zealand, uses two official legal tender currencies. The New Zealand Dollar circulates in parallel with the local Cook Islands Dollar; at the same time, the government also authorises many legal tender coins in the Cook Islands Dollar currency for collector's purposes.
Collector coins are dedicated to historical or general popular culture themes not related to the country itself. Many of them are in standard bullion sizes, including the large three ounces of silver format - such as this coin.
The Coast Guard design is the fourth in the Real Heroes coin series by CIT Coin Invest.
The mint says about it:
As part of the immensely popular "Real Heroes" series, its fourth issue pays tribute to rescue swimmers all over the world, especially those serving in the United States Coast Guard. As one of the six military services, its members have fulfilled their unique duty as both a security and humanitarian force protecting America in domestic and international waters for over 100 years.
While it is involved in all aspects of enforcing U.S. law and trade on high seas, the United States Coast Guard is best known for its daring search and rescue operations including medical evacuations, downed aviators, sinking vessels, floods and hurricanes. To this day, these real heroes save countless lives in need, true to their motto "So others may live". | 
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