# Maritime Master - CalcDeck — Every Formula. 1 App. Offline

> Comprehensive offline maritime calculation toolkit for professionals and enthusiasts. (iPhone/iPad app by MARITIME MASTER LIMITED.)

- Source: https://appshunter.io/ios/app/maritime-master-calcdeck/id6760967809 (this page in markdown: same URL + `.md`)
- Developer: [MARITIME MASTER LIMITED](https://appshunter.io/developer/1107589346)
- Category: Utilities, Education
- Price: Free with in-app purchases
- Rating: 3.00/5 from 1 App Store ratings · 1 written reviews indexed
- Age rating: 9+
- Requires: iOS 17.6 · 7 MB
- Languages: American English
- Released: 2026-05-29
- Data updated: 2026-08-18
- Monetization: free
- User reviews in markdown: https://appshunter.io/ios/app/maritime-master-calcdeck/id6760967809/reviews.md

## What is Maritime Master?

CalcDeck is the complete calculation toolkit for life at sea. It brings 88 professional maritime calculators into one beautifully designed iOS app, covering navigation, celestial observation, tides, stability and cargo, weather, engineering, safety, commercial voyage work, yacht and small craft performance, regulatory compliance and unit conversion.

Whether you are a Master Mariner, deck officer, marine engineer, maritime cadet, yacht skipper or weekend sailor, CalcDeck replaces a shelf of reference books, a scratch pad and a pocket full of single-purpose apps. Every formula is cited with its textbook or IMO source, so you can verify the working and trust the result.

CalcDeck is built by Maritime Master, the team behind COLREG Master, Nav Lights and IALA Buoyage, and is engineered to the same professional standard trusted by cadets and officers worldwide.

What is inside

Navigation (12 calculators): great-circle and rhumb-line distance, course to steer, ETA, set and drift, three-point fix, running fix, dead reckoning, cross-track error, waypoint bearing, speed-time-distance, departure and DMP, Mercator sailing.

Celestial (8 calculators): sight reduction, meridian passage, altitude corrections, sunrise, sunset and twilight times, Polaris latitude, compass error by amplitude, azimuth of the sun, and chronometer error.

Tidal (6 calculators): tidal height by the rule of twelfths, secondary port corrections, tidal streams, height at a given time, time at a given height, and clearance under bridges.

Stability and Cargo (9 calculators): GM and list, trim and draft survey, free surface correction, deadweight and displacement, cargo load, block coefficient, TPC and MCTC, and final draft after loading.

Weather (6 calculators): true wind, apparent wind, relative humidity, dew point, Beaufort scale conversion, and barometric trend.

Engineering (10 calculators): fuel consumption and ROB, daily fuel burn, propeller slip, shaft power, specific fuel consumption, bunker density correction, trim tank transfer, admiralty coefficient, engine load, and voyage fuel planning.

Safety (5 calculators): distance off by vertical sextant angle, horizon distance, dipping range, turning circle, and stopping distance.

Yacht and Small Craft (5 calculators): hull speed, sail area to displacement, displacement to length, capsize screening, and ballast ratio.

Commercial and Voyage (6 calculators): voyage cost, laytime, demurrage, freight rate per tonne, charter economics, and port disbursements.

Regulations and Compliance (6 calculators): MARPOL discharge limits, SOLAS LSA requirements, STCW rest-hour compliance, load line zones, ballast water exchange, and garbage record categorisation.

Unit Converters (12 calculators, all free): distance, speed, temperature, pressure, volume, mass, area, power, energy, angle, time and fuel. Every unit a mariner needs.

Why CalcDeck

CalcDeck works fully offline, so there is no signal, no signup and no interruption when you need an answer at sea. It is a native SwiftUI app designed for iPhone and iPad on iOS 17 and later, with a clean navy and gold Maritime Master design, dark mode support, favourites, and a Calc Pad that lets you pin your most-used tools for instant access on watch. There are no advertisements, no tracking and no subscriptions.

Free and Pro

You can try CalcDeck at no cost. All 12 unit converters and a selection of essential calculators in every professional category are included free. Unlock the full 85-calculator suite with a single one-time in-app purchase that is yours forever across all your devices.

Who it is for

CalcDeck is used by deck officers and Masters on coastal and ocean passages, by marine engineers calculating fuel, power and performance, by maritime cadets preparing for OOW, Chief Mate and Master examinations, by yacht skippers and RYA students, by cruising sailors, by pilots, harbourmasters and port operations staff, and by naval architects, surveyors and marine consultants.

## Key features

- 88 professional maritime calculators
- Offline functionality
- Navigation calculations
- Celestial observation tools
- Stability and cargo calculations
- Unit converters

## Pricing and in-app purchases

Base price: Free.

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| CalcDeck Pro | $4.99 | one-time |


## Recent user reviews (1 of 1)

All indexed reviews: https://appshunter.io/ios/app/maritime-master-calcdeck/id6760967809/reviews.md

### 3/5 — Celsius & Meters.. Sigh

*2026-08-02*

Major stars and likely a rave review if the app had a preference setting permitting measurements in Feet and Fahrenheit.

## Frequently asked questions about Maritime Master

### What is Maritime Master - CalcDeck?

Maritime Master - CalcDeck is a comprehensive calculation toolkit for life at sea. It offers 88 professional maritime calculators covering navigation, celestial observation, tides, stability, cargo, weather, engineering, safety, commercial voyages, yacht performance, regulatory compliance, and unit conversion.

### Does Maritime Master - CalcDeck work offline?

Yes, Maritime Master - CalcDeck works fully offline. This means you can access all its features without needing an internet signal, ensuring uninterrupted use when you're at sea.

### Who is Maritime Master - CalcDeck for?

This app is designed for Master Mariners, deck officers, marine engineers, maritime cadets, yacht skippers, and weekend sailors. It aims to replace multiple reference books and single-purpose apps with a unified, professional-grade tool.

### Are the formulas in Maritime Master - CalcDeck reliable?

Yes, every formula within Maritime Master - CalcDeck is cited with its textbook or IMO source. This allows users to verify the working and trust the results provided by the app.

### What types of calculations does Maritime Master - CalcDeck offer?

The app includes calculators for navigation (e.g., distance, ETA), celestial observation (e.g., sight reduction, sunrise/sunset), tidal calculations, stability and cargo, weather, engineering, safety, yacht performance, commercial voyages, and regulatory compliance.

### Is Maritime Master - CalcDeck free to use?

Yes, Maritime Master - CalcDeck is available for free. It also includes 12 unit converters that are all free to use, covering essential units for mariners.

### What devices does Maritime Master - CalcDeck support?

Maritime Master - CalcDeck is supported on iPhone and iPad devices, making it accessible to a wide range of iOS users.

### How often is Maritime Master - CalcDeck updated?

The app was last updated on May 31, 2026, indicating a commitment to maintenance and potential future improvements. The latest version is 1.0.

## Version history (last 3 releases)

### 1.0 — 2026-05-31

No release notes.

### 1.0.1 — 2026-05-31

Fresh new app icon
Now supports iOS 17 and later, so more devices can run CalcDeck
Performance improvements and bug fixes across all calculators

### 1.1 — 2026-05-29

Audited and crossed checked ready for our launch.

## Apps similar to Maritime Master

| App | Rating | Price | Category |
| --- | --- | --- | --- |
| [SeaRoll](https://appshunter.io/ios/app/searoll/id6756269783) | — | Free | Utilities |
| [MAR-CIS](https://appshunter.io/ios/app/mar-cis/id1234942090) | — | Free | Utilities |
| [DRFT MRKS](https://appshunter.io/ios/app/drft-mrks/id6741070099) | 5.0 (1) | Free | Utilities |
| [Sea Breeze](https://appshunter.io/ios/app/sea-breeze/id6445898579) | — | $0.29 | Utilities |
| [GPS Satellite Tracker+](https://appshunter.io/ios/app/gps-satellite-tracker-plus/id6760257609) | 5.0 (1) | Free | Utilities |
| [CargoMax](https://appshunter.io/ios/app/cargomax/id6755596393) | — | Free | Utilities |

## More apps by MARITIME MASTER LIMITED

- [Tower Defence - Remarkable](https://appshunter.io/ios/app/tower-defence-remarkable/id1643433093)
- [TransPart - Component Search](https://appshunter.io/ios/app/transpart-component-search/id6443449842)
- [Kaleidoscope AR](https://appshunter.io/ios/app/kaleidoscope-ar/id6482973721)
- [Telegraph - API Client](https://appshunter.io/ios/app/telegraph-api-client/id6503224281)
- [Maritime Master](https://appshunter.io/ios/app/maritime-master/id6741146129)
- [Maritime Master Whiteboard](https://appshunter.io/ios/app/maritime-master-whiteboard/id6745555144)

All apps by MARITIME MASTER LIMITED: https://appshunter.io/developer/1107589346

---

*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-18.*