Rare USS Guitarro SSN 665 Submarine Challenge Coin Sub Force. United States Navy USS Guitarro SSN-665 Challenge Coin Mint Condition Challenge Coin. Never Circulated. A beautiful 1.5 inch brass coin with USS Guitarro patch and her service dates on the front. The back is my own copyrighted U.S. Submarine Force design featuring a quote that I know hits a chord with several... "These dolphins, once you pin them on your chest, leave deep marks, over your heart, long after uniforms have been put away" -Bud F. Turner Would make an excellent addition to your collection or for your favorite sailor! Pride Runs Deep! Please note that the actual coin looks MUCH better than the scan shows. Thanks for looking!