FROM THEORY TO PRACTICE - NAVIGATION TO THE COAST
14 November 2011 | closing in on S Africa
With less than 500 miles to go to Durban S Africa this is what is uppermost on my mind. As the weather there can and does change from one 12 hour period to the next, and as the weather forecasts become more accurate the closer we get, we can begin to project Shearwater's position with ever increasing accuracy.
I am now drawing a line from the boat to 30 miles NE of Durban. Im doing this because of that famous 20-30 mile strip barely 50 miles from shore where the current runs south from 2-5 knots. By following this line we will offset that drift south. On the bigger map, the concern is the general current that pulls south in this whole area-much slower but, in a 24 hour period, it can put one in an untenable position too far south. Hence one has to constantly 'crab' north to counter this.
Winds,in the next few days, are predicted to be more healthy, in the 10-15 range. With this increase Im now projecting arrival in Durban Friday into Saturday. However we are getting off to a slow start as this whole night(Monday) the winds are coming out of the west...directly on my nose....means slow progress once again.
As one's actual arrival time can now be predicted with greater accuracy, of utmost importance (and a sleep robbing obsession) becomes the famous Agulhas Current, that same 20-30 mile strip mentioned above. One simply must NOT cross it when a southwest wind blows. Current flowing south against wind blowing north = steep waves. With a SWest wind at 15 it is apparently very uncomfortable. With 20-25 knots it is dangerous. With 25-35+ it can be catastrophic.
And lastly, being single handed, entering a harbor at night is, as Ive said before, not a good idea. So, added to all the other considerations is trying to time it for a day entrance. If not, this one time, I might enter in the dark.
So those are the navigational challenges ahead. Obviously I have never done this notorious leg before so all this has now to go from theory to practice.