I have always thought 12 years was appropriate for pleasure vessels , did mine a couple of years ago, engine and generator room , removed , pressure tested and refilled, also painted with red awlgrip. The quote $1700, the bill $3400, welcome to Miami ! They did discharge both bottles and tested the heat sensors. They mentioned that on some newer boats they visit, the manual discharge did not work because it was not rigged correctly. One thing I did not want to hear is that they are urging insurance companies to mandate a complete inspection of the fire extinguishers every year , even on private vessels.