spent many a day and night making a game out of getting my sextant shot, doing the math and plotting my position. Then when my SatNav took it's position, which was about once every four hours if you were lucky, I would advance my LOP to my DR position and plot it. Then I would plot the SatNav position and see how close I was. I was using HO249 tables and a Sitex SatNav and I got pretty good at it. It was fun but it took a lot of time. It certainly made me better at coast piloting and eyeball navigation.