# OpenSeaMap vs Wattpaddler

The clearest difference is review sentiment: Wattpaddler at 91% against OpenSeaMap's 38%. Wattpaddler also leads on in-app purchases (none vs 1) and iOS requirement (15.0 vs 18.6). On price, update cadence, ads and device support there is nothing between them.

Both are free to download. OpenSeaMap sells 1 one-off in-app purchase. Wattpaddler asks for nothing beyond the download.

OpenSeaMap ships an update every 2 months, Wattpaddler every 4 weeks. The most recent releases landed on November 1, 2026 and November 3, 2026 respectively.

## The numbers

| Metric | OpenSeaMap | Wattpaddler |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[1.0 (1 ratings)](https://appshunter.io/ios/app/openseamap/id495210783/reviews)** | — |
| Number of ratings | **1** | — |
| Positive reviews | 38.3% of reviews | **91.2% of reviews** |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 2 months | **Every 4 weeks** |
| Monetization | Free with in-app purchases | **Free** |
| Size | 13 MB | 36 MB |
| Requires iOS | 18.6 | **15.0** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [appdoctors UG](https://appshunter.io/developer/961029450) | [Steffen Wagner](https://appshunter.io/developer/1489646624) |

## What reviewers say

### OpenSeaMap

[App page](https://appshunter.io/ios/app/openseamap/id495210783)

This app provides a free, worldwide nautical chart with detailed sea information, including lights, weather data, and harbor details. It offers chartplotting, waypoint management, and offline map caching for navigation. Users can mark locations, enter coordinates, and adjust chart zoom for optimal viewing.

**Highlights:** Free worldwide sea chart, Chartplotting with tracking, Waypoint creation and export, Offline map caching, Mark and search locations, Adjustable chart zoom

**Features:** Vision Pro support

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| OpenSeaMap Professional | $1.99 | one-time |


### Wattpaddler

[App page](https://appshunter.io/ios/app/wattpaddler/id1489646625)

Provides tide and water level forecasts for German, Dutch, and Danish coastal areas. Includes detailed weather predictions, storm warnings, and nautical information for safe navigation. Offers tools for calculating passage times and visualizing tidal data.

**Highlights:** Tide and water level forecasts, Weather predictions and storm warnings, Nautical warnings and information, Passage time calculation, Tidal data visualization, Daylight and moon phase information, Interactive nautical charts

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

**In-app purchases:** none


## Frequently asked questions

### Is OpenSeaMap free?

OpenSeaMap is free to download, with in-app purchases available.

### Is Wattpaddler free?

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

### Do OpenSeaMap or Wattpaddler have ads?

Neither OpenSeaMap nor Wattpaddler shows ads.

### Which is updated more often, OpenSeaMap or Wattpaddler?

OpenSeaMap ships an update every 2 months, and Wattpaddler every 4 weeks. Most recently, OpenSeaMap was updated on November 1, 2026 and Wattpaddler on November 3, 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.*