Titanic - From Daunt's Rock to a Collision
A Look at Speed, Revolutions, and Distances Run
A plot of Titanic's maiden voyage transatlantic crossing is shown below. Included are the approximate locations of the ship at local apparent noon for April 12, 13, and 14, as
well as the location of the wreck site (41° 43.5'N, 49° 56.8'W). The distances the
Titanic ran for the first three days of her transatlantic maiden voyage up to noon on April 14
were 484, 519, and 546 nautical miles, respectively. The final distance from noon April 14 to the most likely point where the collision took place at 11:40 p.m. was the sum of
the distance from noon to the turning point at the corner at 42° N, 47° W (about 126 miles), plus the distance from the corner to the
collision point at 41° 45.5' N, 49° 55' W
(about 132 miles). This gives us a distance of 258 nautical miles since noon, a distance which just happens to be in close agreement with the 260 nautical miles through the water
taken off the taffrail log by QM George Rowe at 11:40 p.m.
To get the speed made good over ground we need only to divide the distances run by the elapsed times of the individual runs. The results are given in the table shown below.
It should be noted that the time between Local Apparent Noon (LAN) from one day to next is more than 24 hours because of the westward movement of the ship. The GMT
of LAN for each noontime location was based on the ship's approximate noontime longitude on that date.  The total average voyage speed of 21.44 knots was simply
obtained by dividing the total distance traveled from the Daunt's Rock departure point to the collision point by the total elapsed time from departure at Daunt's Rock to the
time of the collision.