It depends what you really want/need.
Rugged = stay away from hard disc drive camcorders.
Documentary might = interviews and decent audio = camcorder needs a mic jack + manual audio control OR using a "field recorder" for the audio that will replace the camcorder audio during editing.
"Small camcorder" = small lenses and most likely small (single) imaging chip... Likely only the high end of the consumer camcorder area. Small lenses (and small imaging chip = poor low-light video capture behavior. Big lenses and big imaging chips = big camcorder and better low-light behavior. Any camcorder can capture good quality video if the lighting is good and within the acceptable brightness level of a camcorder.
Check what "Survivorman" uses. One small camcorder is a Sony HVR-A1. It is what provides him with the green-tint monochrome night vision ("NightShot"). Depending on the episode, he *could* be carrying two other camcorders. Used to be one or two HVR-Z1's. Now, I *think* he typically is carrying one or two HVR-Z5's. All are miniDV tape based. And a tripod or two. And several optional high-capacity rechargeable batteries. And Pelican 1500 or 1550 cases.
DO NOT rely on only one camera. You are setting yourself up for failure if it dies/breaks or is confiscated/stolen/lost.
I'm going to Afghanistan and require a small, durable, camcorder for shooting a documentary. I'll be in rugged terrain and running around quite a bit, so the camcorder must be small and durable.
Would I need a semi-pro camcorder?