A Tale of Four Ships - April 1912
Tracking the Courses of the Californian, Carpathia, Mount Temple and Titanic
The chart below shows the planned tracks across the Atlantic of four ships: Californian, Carpathia, Mount Temple and Titanic. (Track of Mount
Temple
was modified enroute to a more southerly track taking it well past the corner point [42°N, 47°W] to avoid reported ice. The
Californian planned to stay on 42°N from the corner till 51°W before heading up to Boston.)
Below is a chart of the area [reproduce from my THS Commutator article] extending from 40° 20’ N to 43° 40' N, and 46° W to 52°
W. Included is a set of possible current vectors that were modeled somewhat after modern satellite data as explained in the article. Near the center
of the chart, centered about 41° 40’ N, 49° 25’ W, is placed a cold water eddy with the usual counter-clockwise circulation with a
core that is about 40 nautical miles in diameter. Feeding into this is a strong Labrador current out of the north which is converging with a somewhat
meandering Gulf Stream current flowing from the west, looping around southward, and finally veering off the north-northeast on the eastern side of
the eddy. Included on the chart are tracks of four ships:

  The DR track of the
Californian with its reported noon location at 42° 05’ N, 47° 25’ W, and heading 269° true from there
toward 42° N, 51° W as reported by Capt. Lord in his 1959 affidavit.
  The  DR track for the
Titanic based off of a derived 7:30 p.m. ATS celestial fix position (corrected for a 15' longitude error) at 41° 52.5’
N, 47° 53’ W, and heading 266° true from that fix.
  The DR track of the  
Carpathia with her DR location for 12:35 a.m. ATS at 41° 10' N, 49° 13' W, where she altered her course to  
308° true (N 52 W) for the Boxhall CQD (SOS) position at 41° 46' N, 50° 14' W. Prior to that, she was on a Great Circle course toward a
point due west of Gibraltar.
  The DR track of the
Mount Temple with her DR location for 12:26 a.m. ATS at 41° 25' N, 51° 14' W, the time when she altered her
course to a heading of 065° true (N 65 E) for the CQD position. Prior to that she was on rhumb line to Cape Sable Island from 41° 15' N,
50° 00' W having come down there from the corner to avoid reported ice.

For a complete explanation of how the local current may have affected the course of each ship in the region, please refer to my THS
Titanic
Commutator
(No. 177) article, "Light on the Horizon," Part 1.
Shown below is a summary diagram of funnel colors used on steamers in 1912. Funnel colors were often used to easily identify the steamship line
that a steamer belonged to when first seen at a distance.