But it's not just sailing!
Pick any "old art" that leads to any sort of self sufficiency. The sad fact is, much of our skill base and brain exercise is being co-opted by technology.
Ask yourself; how many phone numbers can you remember off the top of your head, and how many do you ask your cell phone to remember for you? (I'm particularly guilty of this one!)
I read somewhere that 100 years ago it was possible for a single individual to have a working understanding of the entire range of human knowledge. Tnat is simply not possible now.
As a species we are sowing the seeds of our own destruction. Now, I am no luddite. I embrace technology as much as the next fellow. However, I try to be conscious when I make a decision to abdicate a responsibility to a technological fix; and I make a concerted effort to retain the skill and knowledge base to do it myself.
Navigation for example. I LOVE GPS
! However, I practice the old arts, and will make damn sure to fully learn celestial navigation when I begin long term cruising.
I don't HAVE to heat my home with wood; but I'm damn sure gonna be ABLE to!
And so on..... And so on......