# Nautical Calculator Preview vs Nautical Rules

The clearest difference is ads: Nautical Rules at none against Nautical Calculator Preview's shown. Nautical Rules also leads on ratings volume (12 vs 1) and monetization model (free vs ad-supported). On price, rating, update cadence and in-app purchases there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

On the App Store both sit at effectively the same score — 5.0 for Nautical Calculator Preview against 5.0 for Nautical Rules. That said, the two scores are not equally well evidenced: Nautical Rules has 12 ratings behind it against 1, so its average is the more settled of the two.

Nautical Calculator Preview ships an update every 2 weeks, Nautical Rules every 3 weeks. The most recent releases landed on October 7, 2026 and October 23, 2026 respectively.

## The numbers

| Metric | Nautical Calculator Preview | Nautical Rules |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [5.0 (1 ratings)](https://appshunter.io/ios/app/nautical-calculator-preview/id1534074231/reviews) | [5.0 (12 ratings)](https://appshunter.io/ios/app/nautical-rules/id6756220989/reviews) |
| Number of ratings | 1 | **12** |
| Positive reviews | — | 100.0% of reviews |
| In-app purchases | No | No |
| Ads | Yes | **No** |
| Update frequency | **Every 2 weeks** | Every 3 weeks |
| Monetization | Ad-supported | **Free** |
| Size | 33 MB | 5 MB |
| Requires iOS | 17.0 | 17.0 |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [The Vu Cong](https://appshunter.io/developer/1532372627) | [Joseph Kim](https://appshunter.io/developer/1855404156) |

## What reviewers say

### Nautical Calculator Preview

[App page](https://appshunter.io/ios/app/nautical-calculator-preview/id1534074231)

This app provides comprehensive tools for marine navigation, including real-time ship movement, route planning, and advanced sailing calculations. It also offers features for collision avoidance, maneuvering, and learning maritime regulations and signaling.

**Highlights:** Real-time ship movement, Route planning, Mercator and Great Circle sailing, Collision avoidance, Maneuvering calculations, COLREGs and maritime signaling, Offline GPS

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


### Nautical Rules

[App page](https://appshunter.io/ios/app/nautical-rules/id6756220989)

Master USCG Navigation Rules with a comprehensive question bank and smart study features. Track your progress, practice for exams, and study offline to navigate with confidence.

**Highlights:** 1,200+ practice questions, Inland and International waters coverage, Detailed explanations, Customizable tests, Offline study capability, Progress tracking dashboard, Accuracy by rule statistics

**In-app purchases:** none


## Frequently asked questions

### Is Nautical Calculator Preview free?

Nautical Calculator Preview is free to download, with no in-app purchases.

### Is Nautical Rules free?

Nautical Rules is free to download, with no in-app purchases.

### Which has better reviews, Nautical Calculator Preview or Nautical Rules?

Nautical Calculator Preview and Nautical Rules are both rated 5.0 out of 5 on the App Store, from 1 and 12 ratings respectively.

### Do Nautical Calculator Preview or Nautical Rules have ads?

Nautical Calculator Preview shows ads; Nautical Rules does not.

### Which is updated more often, Nautical Calculator Preview or Nautical Rules?

Nautical Calculator Preview ships an update every 2 weeks, and Nautical Rules every 3 weeks. Most recently, Nautical Calculator Preview was updated on October 7, 2026 and Nautical Rules on October 23, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*