Is Dead Reckoning really a practiced art?
I've wondered about "Dead Reckoning." The way I've heard it used sometimes amounts to; "Well--I reckon it must be over there!" Seriously, for how many hours of travel, at say 6.5 kt, should one trust a DR plot? If you're updating your position plot every hr w/ GPS (until it fails) you'd have a baseline for drift and set "behind you!" But then the tide reverses during a new moon and you still have, say, 9 hr of travel after dark to destination with another tide reversal in the offing. Where would you really be at the end of those 9 hr lacking a fix on a lighted ATON? Now I realize that big-time ocean sailors can go days to weeks on DR (if they have to) and not be too far off when a fix is finally gotten. But what about when traveling along the coast where tides, currents, and local eddies potentially come more into play? How often does anyone practice with the GPS TURNED OFF? My guess is hardly ever to never b/c the position up date is continuous while the GPS is working--no need for DR plotting until it STOPS working. Whereas in the old school, one had to maintain DR plots between fixes b/c they could be gotten only one or two times a day, maybe, unless passing within sight of charted landmarks, etc.
