The reconstruction of the course of the submarine H.50 was done with the
help of these elements in the log books:
| 0600 UT | 270° | 9.6 NM in the preceding hour |
| 0700 UT | 270° | 8.6 NM in the preceding hour |
| 0728 UT | 290° | |
| 0800 UT | 290° | 9.0 NM in the preceding hour |
| 0851 UT | 300° | |
| 0900 UT | Jetty | 8.8 NM in the preceding hour |
All courses are true. The submarine’s positions are represented by the white squares. The point at 20 NM to the southwest of the Needles is represented by star and the point at 20 statute miles by the black circle. The positions given by the newspapers are represented by black diamonds.
British Summer Time = UT + 1.