Navigating by heavenly bodies is a fascinating skill to have, but the main frustration is not being able to take meaningful sights with your sextant (even if you had one). This practical session will demonstrate the use of a planetarium app as a sextant simulator, being part of a full position fixing scenario starting with the date (the morning after the talk) and your vessel's Dead Reckoning (DR) position. With the scenario set, we will then plan the sight times, look at a selection of the best heavenly bodies and take the sights using the app. These will be taken through the "chosen position" method of sight reduction to yield your fix and all without leaving your armchair! Sun, moon and other Mer Pass sights will also be demonstrated along with constructing your own plotting sheets and a list of web sites giving access to all the almanacs and tables required.
Participants should preload either of the two recommended apps, Winstars 3 for Windows PCs or Stellarium Mobile or Mobile Plus for iPhones and Android phones or tablets and follow the position fixing scenario during the talk. Also bring a pad and pencil to note down the sights.
Date: Sunday 24 July 2022
Time: 10:30
Place: CA House
Booking: Book venue
Cost: Talk: members £20.00, non-members £25.00. Lunch will be 'pay on the day' either a buffet or 'your choice from menu', depending on numbers.
Pre-lunch talk and practical (1 - 1½ hours)
Setting up a scenario : Following with group participation - Quick overview of taking the sights : Short discussion of the sight reduction process : Complete the position plot using plotting sheet : Repeat plot using "TeacupNav" plotting software.
Post-lunch (½ - 1 hour)
Taking sun and moon sights : Construction of the latitude scaling sheet and use of standard graph paper.
Our Speaker: Andy Johnson - spent many years as an Electronics Engineer in aerospace and semiconductor industries followed by ten years as an RYA practical and shore based instructor. Most recently he worked at Raymarine as a quality assurance test engineer mostly out on the water stressing their latest kit! He is the author of "The Boat Electrics Bible" commissioned by Adlard Coles and recently released his own book "Astro Navigation from Home" published through Brown Dog Books and supported by the astronavfromhome.co.uk website. He has been sailing pretty much all of his life and he and his wife Sue own Supernova, a Moody 336.