Max, Dave, SD
Here is the real deal in Canada: I am a CCGA-P member. I have been doing CEs (Courtesy Examinations) for about 15 yrs. Until last year, we would inspect the fire extinguishers, but ignore the tag. However, if you got boarded by the RCMP, they enforce the Provincial Fire Code, as well, where the rule has always been to require current tags. Then CCG moved to Transport Canada and the rules now require CEs to include a tag check on all fire extinguishers. You have to be current, or no sticker. This is ok at our YC's Safety day, as the Fire guys are there and well organized, so hundreds of FEs get tagged in one day at no charge. For anyone who misses Safety Day, its a trip to a fire tagger and a small fee for every one. In addition are the 5 and 10 yr requirements that Dave mentions.
The absence of a CCGA CE tag is not a condemnation of your boat or its maintenance, but the presence of a sticker means to the CCG or the RCMP, if coming close to your Stb side, thta this is a boat that meets all current safety standards, so you will get fewer hassles.
Dave, there is no such thing as a redundant fire extinguisher. I think you mean "backup".
For boats over 12m (40ft) a fire axe is required.
The rest need at least a pair of buckets capable of carrying 10l of water, not sand.
The bucket of sand is only for boats that carry a ship's cat.