Thread: Running Fix
View Single Post
  #33   Report Post  
posted to rec.boats.cruising
Dawson Dawson is offline
external usenet poster
 
First recorded activity by BoatBanter: Feb 2009
Posts: 1
Default Running Fix

The 1210 TR chart (Martha's VIneyard to Block Island) is one of the
"frozen datum" charts. The chart was "frozen" in the 1960s so they
would not have to keep rewriting the textbooks & exams every time the
chart was updated. Obviously not for actual navigation anymore! -- but
they are fun to look at for the flavor of the cruising ground.

Another TR chart is the 116-SC, which shows the N part of Long Island
Sound in the vicinity of Mystic CT and close-up charts of some rivers
in CT -- useful to train on for in-tight navigation.

And it's interesting to look at the 39 TR chart, which shows the W end
of Lake Erie. Interesting because it's a Polyconic projection, not
Mercator -- used for the Great Lakes. Some folks who are trained on
the coasts & move to the Great Lakes have trouble with this. These
charts also use statute miles, not nautical miles -- an odd sensation
of always "getting it wrong" when you have become accustomed over
years of experience at estimating how fast you're going & how far
you've traveled over ground.