Simulacrum said:I keep separate Shiphandling and Navigation skills. A captain uses his Shiphandling skill to keep a course that he is either familiar with already or has been given him by someone who has plotted it using a Navigation skill. Navigation my use stars as a sense check, or when out of sight of land, but landmarks, prevailing winds, tides, currents etc will also be important parts of the skill.
True. Only when the compass and astrolabe came into widespread use did mariners voluntarily sail outside sight of land, and instead mostly used dead reckoning. Although there *was* an variety of astrolabe in Hellenistic times, and it appears Yemeni merchants may have done a direct sail from India to Aden across open ocean during the favorable monsoon.
But your seafaring captain would have been able to use the stars to gauge the start of that monsoon, and would certainly understand the meterological and astronomical adages about red skies and neap tides... or whatever equivalents those have in various fantasy settings.
Having sailed a bit myself, I can report that the "Shiphandling" skill consists primarily of knot tying and sky watching.
