Re: Circumnavigation without instruments
Boasun.... Yes, you are correct. However, things are a little more complicated and uncertain when you add drift (current) and leeway (especially when traveling under sail). After a few miles, depending on conditions, your actual course vs. DR course may start to diverge noticeably. I'll omit small "discrepancies" in steering the course... Your point that you may well be without celestial observations for a prolonged time is certainly valid and thus one should always be prepared for "the worst" and keep a DR log up at all times, regardless of other gadgets available.