The Coast Guard is launching a program to replace its Hamilton (WHEC-715) and Bear (WMEC-901) class high- and medium-endurance cutters just as the Navy is getting rid of its Oliver Hazard Perry (FFG-7)-class guided-missile frigates. There are some obvious possibilities here.
The 12 Hamilton-class cutters entered service between 1967 and 1972; the 13 Bear-class cutters became operational between 1980 and 1988. The lead ship of the Oliver Hazard Perry class was commissioned in 1977; between 1981 and 1985, an average of seven ships a year entered service. The last ship of the 50-ship class, the USS Ingraham (FFG-61), was commissioned in 1989. Most have at least 15 years of service remaining.
The FFG-7s carry Harpoons and Standard missiles (SM-1s). Given the Coast Guard's mission of enforcing U.S. drug, environmental, fisheries, immigration, and maritime laws, it does not need them.