Gentlemen

,
Thank you for your comments.
For the benefit of the Lurkers, I will post some quotes from Wisman's SAS Guide. Anything not in "quotes" is a comment by me.
"A multi-bladed penknife is useful, but if you can carry only one knife, take something stronger, a general-purpose blade that will do all likely tasks efficiently and comfortably, from cutting trees to skinning animals and preparing food."
"Parang: The Malayan name for a large curved blade like a machete. ...it is ideal for cutting down trees and building shelters and rafts. The ideal Parang size is 12inch overall blade length, with a blade 2inches at it's widest, weighing no more than 1.5 lb. The end of the blade should be bolted into a wooden handle".
An illustration shows a parang and describes how it should be sharpened in three sections. The tip area should be very sharp and is used for skinning animals. The area near the handle should be kept sharp enough for carving and delicate work. The center section is sharpened at a more obtuse angle and is good for chopping wood.
Another illustration shows a medium size belt knife with a double guard, stick tang and pommel nut.
IMO, the small knife or SAK has been suplanted in the modern era by the multitool. They are stronger and safer than a penknife or SAK.
A medium belt knife is certainly a great asset; however, if you only have one cutting tool, I agree with Wiseman, carry one in the 12" or larger size, but not too thick and heavy. In Africa, Asia, Latin America and other places, if an indigenious person only has one knife, it is a large one. It may be called by many names, parang, machete, golock, bolo, panga, kukri, etc.
Steve