2 48° South 074° West
"Angostura Inglesa" is, without a doubt, the most important natural obstacle in navigating the South American channels, as it is a winding step that requires two changes of course close to 90 °, subject to a tidal regime and Considerable currents, which is also affected by the frequent bad times of the Gulf of Penas, forces sailors to face it with caution and take adequate security measures.
This video shows an introduction on the Spiral-Test-Manoeuvre and describes the procedure how to steer through this manoeuvre and measure the data needed. The results will be displayed in a characteristic diagram allowing to identify stable and unstable conditions and related, detailed information, e.g. spiral loop width and height, rudder angle of neutral effect. Samples of stable and unstable ship behaviour demonstrations will be shown by Fast Time Simulation using the SAMMON Planning tool.
