NavList:

I was reminded yesterday of some of the silly games we would play at sea when racing.  One of these (in suitable weather) was a competition to guess the (ship)time when the first star would be seen at evening twilight, and then a competition to spot the first star.  Guesses had to be in the book by sunset.  As the navigator I would have my options for star sights worked out in advance (Volume 1 of the Air Tables) and getting the crew on deck to play this game meant helpers when I needed them.  Unfortunately the crew tended to tire of this after a day or two (seeing through my nefarious plot). 

Yesterday evening was relatively clear in the Pacific Northwest, so I chose 4 of the 7 stars for my time and latitude, made my guesses and went outside with sextant, compass and a pair of binoculars.  I thought I would see Jupiter before the first star.  I was wrong.  Jupiter did not appear (through some haze) until I had seen both Sirius and Procyon.  I guessed Sirius first, and was correct, but was 6 minutes late against my estimate.  And so on.  Clouds, haze (and trees etc if on land) etc are all valid obstructions each guesser must consider.

Anyway, it is a bit of fun to play with the famly (kids, grandchildren and so on) and provides a teaching opportunity including an introduction to whatever tools you use to work out in advance which stars will be where, their magnitude, the time of twilight etc.

Murray