Friends of mine live on a sailboat. For thirteen years, they have been traveling the oceans of the world, coming ashore from time to time. They are now in their early sixties and do not have medical insurance. They use two medical guides to help them diagnose and treat ailments:
The Onboard Medical Book by Paul G. Gill, Jr., M. D.
Merck Manual of Medical Information, Home Edition
Another book has been recommended for similar circumstances:
Where There Is No Doctor (1977) by David Werner
If you would like to read what life without insurance has been like for my sailing friends, click here:
http://justalittlefurther.com/faq-medical-care/
I'm Off My Meds Again 