Coastal offshore I would do without a raft, deep ocean no way.
I somewhat agree with you Andre re the EPIRB but if I sink someone is going to notice and at some point a search is going to be undertaken at considerable cost to the community at large. If S&R had the EPIRB signal that search would hopefully be shorter and less expensive.
In the case of the Hiscocks we should remember that had they gotten into trouble offshore a full scale S&R would not have been undertaken if only because without EPIRB their known position would have been hazy at best. Its also fair to say that S&R operations and equipment was nowhere near the level of sophistication we see today and finding a yacht in distress or a life raft would have been pretty much hit and miss.
"Said Hamlet to Ophelia, I'll draw a sketch of thee.
What kind of pencil shall I use? 2B or not 2B?” Spike Milligan