Author Topic: What are they doing?  (Read 4494 times)

Randi

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 12823
    • View Profile
Re: What are they doing?
« Reply #15 on: August 26, 2015, 03:38:43 pm »
Pioneer is a US Coast and Geodetic Survey Ship.  See http://www.history.noaa.gov/ships/pioneer1.html

These ships want to know everything about the shape of the coast, and the shape, depth and composition of the sea floor, and the state of currents in the area in order to make charts for safe navigation.

Charts produced by these ships can be seen at http://www.nauticalcharts.noaa.gov/csdl/ctp/abstract.htm

Reading Two Years Before the Mast (1834-1836):
Quote
The soundings on the American coast are so regular that a navigator knows as well where he has made land, by the soundings, as he would by seeing the land. Black mud is the soundings of Block Island. As you go toward Nantucket, it changes to a dark sand; then, sand and white shells; and on George's Banks, white sand;
...
On Monday morning, the increased depth and deep blue color of the water, and the mixture of shells and white sand which we brought up, upon sounding, showed that we were in the channel, and nearing George's; accordingly, the ship's head was put directly to the northward, and we stood on, with perfect confidence in the soundings, though we had not taken an observation for two days, nor seen land; and the difference of an eighth of a mile out of the way might put us ashore.
(They are approaching Boston.)

AvastMH

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 7048
    • View Profile
Re: What are they doing?
« Reply #16 on: August 26, 2015, 04:18:09 pm »
interesting! (I've always meant to read that book - must get around to it one day  ;) )