Astramate

Astramate is an offline-first maritime calculation toolkit designed for seafarers, deck officers, cadets, and maritime professionals. It provides practical calculation tools with visible formulas, clear working steps, input validation, and warnings to help you understand how each result is produced. FEATURES • Voyage calculations • Compass calculations • Loading calculations • Draft and stability tools • Maritime unit converter • Linear and bilinear interpolation • Vessel profiles • Calculation history • JSON backup and export • Searchable formula and tool library • Offline-first operation Astramate includes maritime calculation tools for tasks such as ETA, distance, average speed, compass error, true and compass conversions, stowage factor, cargo volume, cargo weight, draft calculations, trimming calculations, and other onboard utilities. FREE Access core calculation tools with advertising. 3-DAY TRIAL Access all tools with an ad-free experience during the trial period. PREMIUM LIFETIME Unlock all Premium tools, additional vessel profile features, full history/export functionality, and an ad-free experience with a one-time Apple In-App Purchase. No online account or sign-in is required to use Astramate. IMPORTANT Astramate is a calculation and reference aid. Results should always be verified against approved vessel documentation, official publications, company procedures, and applicable maritime regulations before operational use.