Thank you every one great responses and links, the other day a bunch of charts and a few how to books arrived, I'm looking forward to trying to learn something new. Ever since early childhood my farther told me on every vacation he took me on I had to learn something new in relation to the theme of the vacation, I learned simple French on a trip to Paris, etc., etc., etc., Sextant on a cruise is what I'm down to after about 14 or so cruises.