Well, my $0.02 worth is based on several tours (I'm over on one now) and enough time in that I can retire when this tour ends. I've made most of the normal mistakes, and found what works for me. First, big blades are rarely used, and they're way too heavy to carry around all the time. Second, Japanese style blades too specialized, as they don't have the ability to do much more than slashing cuts and punctures. If he's going into the field a 4"-5" knife is about right. I prefer a drop point, but a clip would do also. Don't go getting one of the super hard to sharpen steels; he's going to need to put an edge on it, and he'll have minimal gear. It needs to be strong enough to be whacked with a rock or a board to cut or split something, but not a "crowbar". Don't get a "fighter" or a "skinner" pattern. Get a knife with a grip that's not too big (he'll be wearing gloves a lot). Don't worry about the sheath; you can have one custom made if needed, but everything attaches to Molle. Currently I've got two fixed blades; a chute knife from Tim Hartman and a recurve by Matt Bailey, both of which you can find photos of on this board. If I had to take just one from my collection my current tastes would be a 4" from Centofante that's in storage right now. Frankly, I don't use the fixed blade that often. What I do use are the folders; a whittler, a little Buck with three small blades, and a Case/Bose back pocket. My guess is that, as a medic, your son is going to need some small, sharp, blades a lot more often than any big ones. I'd also suggest he pick up the following: several really good tweezers, a couple good nail clippers, and a couple small scissors. Those will be impossible to come by in country, and he's going to see a lot more small injuries than big ones (I hope).
