A quick note on the visual detection ranges, particularly in the South Atlantic. I should mention that I'm on a ship down to the Canaries lecturing and one of the other lecturers is none other than Michael Nicholson, ex-ITN who covered the campaign with Brain Hanrahan on Hermes and other ships at the time. I had a very pleasant chat about his voyage which I will expand on when i get a cheaper internet connection. Its $1 a minute on board.
Anyway back to visual detection ranges for those interested. The longest recorded visual detection of one ship by another was in 1939 by the Graf Spee when she detected a contact visually at 53,000 meters (!) which she subsequently sank. I able to put this partially to the test today and with a good pair of bins on a murky overcast January day. I could easily make out container ships at 11 miles and beyond.
The South Atlantic is so clear and un-polluted that this is possible, although I am not claiming this to be so in the case of AC given the time of day and the time of year. My dead reckoning position for AC may also be out as it is taken from Alacrity's track chart. Her satnav system was inoperable from Ascension southwards, so there may be some margin for error depending on when her last Astral fix was taken. Also as you get near to the poles, spurious radar targets become more common. I understand that at least two ships engaged targets beleived to be enemy surface vessels with guns which turned out to be anaprop.
Anyhow a nice sunny day in Lisbon beckons tomorrow. If anyone remembers Michael Nicholson, I'd be very pleased to say hello for you.