This might be common knowledge by now but today the Federal Consumer Protection group has issued yet another recall for the common Kidde fire extinguishers. Many of the  extinguishers were sold as 'Marine Class' units by many outfits and under several different labels both in the US and Canada. Some 37 million units are affected.
I found we had one of the recalled units on board and just for kicks, tried to set it off (in the back yard). Much to my surprise the unit did not work and it still read a 'full charged' state. 
I'd urge you all to check this recall and your extinguishers.
See:  https://www.cpsc.gov/Recalls/2017/kidde-recalls-fire-extinguishers-with-...