The availability of a surgeon was often considered vital to any expedition - and this was especially so among pirate or buccaneers crews. Sometimes surgeons would willingly volunteer to join an expedition, attracted by the scientific opportunity to travel and observe new flora, fauna, or disease; but as often as not a captured surgeon would be forced to serve in a crew against their will. Just as important on the frontier would be the shamans or medicine men, and few raids would set off without the availability of their powders and spiritual guidance.