Orastra vs CHIEFMATE

Orastra is an offline celestial navigation aid for mariners, students, and anyone learning practical sight reduction workflows. Plan and review observations, work from a dead reckoning reference, inspect almanac material, and plot celestial fixes on a single map-based interface. Orastra is designed to keep celestial reduction separate from GPS, so any GPS position shown in the app remains a reference overlay only and is not part of the reduction itself. Features: Offline celestial navigation workflow Dead reckoning reference and running-fix support Map-based plotting for DR, celestial fixes, and reference GPS Almanac access and onboard reference material Sky guide and time tools for observation planning Logbook for saving and reviewing fixes Navigation aid only. Results depend on observation quality, timing, and correct operational use. All inputs, outputs, and navigational decisions must be independently verified.

CHIEFMATE is a professional maritime navigation companion built for mariners who need tools that keep working when everything else goes dark. WORKS OFFLINE, NO SIGNAL NEEDED Even in airplane mode, far offshore, CHIEFMATE computes celestial navigation entirely on your device: • Sight reduction (intercept method) for the Sun, Moon, planets, and all 57 navigational stars. Enter your sextant altitude and get a line of position. • Sun & twilight: sunrise, sunset, meridian passage (LAN), civil and nautical twilight windows, day length, and sunrise amplitude. • Latitude at noon (LAN) and by Polaris. • STCW / MLC hours of rest compliance. Positions are computed to arcminute accuracy, finer than a sextant resolves, using a built-in solar model and a bundled astronomical ephemeris. No internet, no subscription, no account required for the offline tools. THE FULL PLATFORM WHEN YOU'RE CONNECTED Sign in with your CHIEFMATE account to open the complete platform: charts that work offline, weather routing, electronic logbooks, tides and currents, stability and loading, publications, emergency procedures, and an AI watch assistant. BUILT BY MARINERS, FOR MARINERS CHIEFMATE is one connected workplace: a sight reduction flows into your logbook and plotting sheet automatically. It runs on a rugged shipboard computer, on the desktop, and now in your pocket. Use CHIEFMATE alongside official publications, a paper almanac, and sound judgment. It supports your decisions. It does not replace prudent seamanship or required carriage equipment. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ CHIEFMATE is a product of STEM Maritime Systems LLC.