CaptainCalc is a captain-made marine navigation toolkit for ship captains, deck officers, maritime cadets, and professional seafarers who need reliable tools at sea.
Plan voyages, prepare offline map packs, check vessel stability, calculate celestial navigation sights, track GPS position, and keep essential onboard records in one focused maritime app.
★ CAPTAIN-MADE MARITIME TOOLKIT
CaptainCalc was built from real onboard experience, not as a generic calculator with nautical labels. It is designed around the practical decisions, limited time, and working conditions faced by captains and officers at sea.
★ OFFLINE MARINE MAPS
Prepare before departure with supported downloadable offline map packs. Keep essential map context available when mobile data is limited offshore, review routes with more confidence, and reduce reliance on constant connectivity during voyage planning.
Offline map workflows help you plan ahead, download supported regional or harbor-detail packs where available, and keep your maritime tools usable when signal drops.
★ CELESTIAL NAVIGATION
Calculate sun, moon, and star sights with practical celestial navigation tools designed for shipboard use. Useful for training, backup navigation practice, and professional maritime workflows.
★ SHIP STABILITY TOOLS
Use vessel stability tools to support daily stability checks and operational planning. Built for captains and deck officers managing real onboard conditions.
★ VOYAGE PLANNING
Organize routes, review passage details, track progress, and keep voyage information accessible throughout the journey. Combine voyage planning with GPS position tools and offline map support.
★ NAUTICAL CALCULATORS
Access fast marine calculators for common onboard calculations. Save time, reduce manual errors, and keep essential maritime computations close at hand.
★ GPS POSITION & TRACKING
Use GPS-based position tools to support situational awareness, location checks, and onboard logging during maritime operations.
★ ONBOARD RECORDS & LOGS
Keep operational notes, history logs, voyage data, and reference information organized for daily shipboard work.
CaptainCalc is useful for:
• Ship captains and vessel commanders
• Deck officers and navigation officers
• Maritime cadets and nautical students
• Professional seafarers
• Mariners who need offline-capable voyage tools
Designed for life at sea, CaptainCalc keeps the interface clear, fast, and focused. No clutter, no distractions, just practical marine navigation and ship operation tools when you need them.
Subscription & Free Access:
Core features are available on the free tier. Advanced maritime tools, offline map workflows, and professional voyage features may require a subscription. Free trials may be available through Google Play for eligible users.
Important:
CaptainCalc is designed to assist maritime work and nautical training. It is not a substitute for certified navigation procedures, official onboard documentation, approved nautical charts, ECDIS, company instructions, flag-state requirements, or applicable regulations. Users remain responsible for all operational decisions.