We have always carried what we call a "Ditch" bag... as in, if you have to ditch the boat, this stuff will be important. It contains a first aid kit, flares, signal mirror, whistle, strobe, some line, Leatherman, hand-held VHF, waterproof matches, and probably some more stuff that I'm forgetting right now.
We have always kept this near the companionway in our sailboats. If you need any of those things (without the need to ditch), they are in one place. HTH
Best wishes,
Jim B.