My US purchased boat came with 8 USCG approved PFD that became non-approved the minute the boat came under Canadian registry in Canadian waters. I called the CCG, plus the Transportation Industry Ministry with the Mfg number to see if there was a corresponding CCG number that I could obtain. No such luck although the USCG and CCG approved ones are made by the same Mfg and are exactly the same.
Since the requirements say they have to be on board (does not say worn all the time) I bought a bag of CCG approved PFD and keep them on board. Stupid as it is the CCG approved ones I bought are of a lesser quality, i.e. provide less buoyancy than the USCG ones that came with the boat ! If we ever need to put them on, you can bet that everybody on board will don the USCG approved ones.
BTW, I remember reading that in Canada, an inflatable PFD, automatic or manual, only counts if worn all the time.
As for flares, I keep a supply of old ones on board. More are better I believe. But most people seem to think that they are for signaling an emergency. Good luck with that if offshore ! They really should be used to signal your presence to approaching help.