Review on 🌟 Enhanced Celestial Navigation Bundle: Davis Sextant Mark 3, Celestial Navigation 132, and Davis Artificial Horizon 144 - Advanced Tools for Navigational Accuracy (3 Items) by Bill Forbis

First the bottom line. You can't go wrong with this Davis Mark 3 sextant or artificial horizon. The Mark 3 is a fantastically well thought out design that makes the most of the technical properties of the plastic. How amazing that a $50 set can compete with traditional metal sextants like the Astra IIIb that cost 15 times more. When photographing the Sun, Moon, or Venus from the Davis artificial horizon, I typically get a line of reference within 5 miles of my coastal location. . The averaging of several oscilloscopes reliably leads to better results, which indicates a small systematic error. This makes the Mark 3 not only a great tool for vision training, but also as a backup ditch bag, for measuring horizontal angles when flying, or even as a primary navigational aid if that's the task you're looking for. A rapid series of six ground-based images of the Sun that returned an average position line error of 0.1 mile with an error of one mile. Call it a coincidence, but still. At sea, of course, it's a different matter. Find latitude and longitude with the help of sun visors and watches. It also has an almanac with approximate solar declinations and the equation of time. In fact, that's enough to go around the world. Davis' artificial horizon is a great tool for getting points of interest from a known coastal location, even at night. It's compact, durable and does its job well. It comes with two clear glass panels, two colored solar panels and two triangular supports. All parts fit perfectly in a 4 x 6 x 1 inch water tank that doubles as a storage box. Rays of light pass through both glasses at opposite angles, so there is no refractive error unless you mix glass and plastic. The glasses protect the water from the wind by becoming still image This is the main advantage of the Davis over a bucket or deep bowl. Use very cold water at night to prevent condensation from forming on the glasses. Remember to adjust the range for an index error and then divide by two as the reflection will double the height. No drop of correction required as there is no drop. Don't expect to shoot stars other than the Sun, or the brightest ones at night, as their reflection off the water is too weak. Navigating planets is fair game. Altitudes below 10 degrees will be difficult due to the rim of the reservoir and high altitudes being limited to half the arc of your sextant, 65 degrees for most but 50 for the Davis Mark 3. (I only bought the sextant and horizon, so can't speak to the quick start guide. From his own reviews, I concluded that this is a good refresher and the price of the kit is slightly reduced, but you'll have to look elsewhere for niceties. For that, I heartily recommend Astronomical Navigation in the Age of GPS by John Karl This is my favorite book on the subject.) A few minor caveats. Mark 3 is sensitive to handling and temperature changes because it's made of plastic. So remember to note the index error often when there is a temperature gradient between the sextant and its surroundings. I've found that getting to a good baseline is kind of an iterative process with pauses in between. The reason seems to be that once adjusted, the two set screws take time to equalize as they are balanced with the plastic and mirror clips. .As other reviewers have noted, the combined hues can become darker than when photographed in the sun. I'm surprised the manufacturer didn't address this as it would have been an easy fix. Some notice the shift in the horizon mirror. It is pressed in and not adjustable. Mine is perfect so it seems to be due to manufacturing tolerances. In this case, the manufacturer is willing to send you a new sextant, so it is not new. In summary, the Davis Mark 3 Sextant is a serious instrument with elegant simplicity that can serve a variety of motives: student of the timeless art, as a backup in case your GPS fails, as an item for your ditch bag, as an instrument for steering or just for sports . If your goal is ultimate accuracy or owning a high-precision instrument, then choose the Astra IIIb. Adding an artificial horizon is a great idea as you can view your sights day or night from your yard or building rooftop while benefiting from the practice. easier to achieve and possibly more frequent. This winning pair greatly improved my entire routine, from aiming to the reduction mechanism. A brief instruction completes the set.