# PredictCurrent vs Slackwater

The clearest difference is review sentiment: Slackwater at 100% against PredictCurrent's 57%. Slackwater also leads on rating (5.0 vs 4.5). PredictCurrent's advantage is ratings volume (272 vs 1) and chart position (#70 vs unranked). On price, update cadence, ads and in-app purchases there is nothing between them.

Both are free to download. PredictCurrent sells 5 in-app purchases, starting at $15.00 per month and Slackwater sells 2 in-app purchases, starting at $7.99 per year. Whichever you choose, the download price is not the number that matters.

Slackwater holds the better App Store score, 5.0 against 4.5. That said, the two scores are not equally well evidenced: PredictCurrent has 272 ratings behind it against 1, so its average is the more settled of the two. Written reviews point the same way: 57% of PredictCurrent's written reviews are positive against 100% of Slackwater's.

Both ship on a similar rhythm, roughly monthly. The most recent releases landed on November 12, 2026 and November 11, 2026 respectively.

## The numbers

| Metric | PredictCurrent | Slackwater |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.5 (272 ratings)](https://appshunter.io/ios/app/predictcurrent/id6468610449/reviews) | **[5.0 (1 ratings)](https://appshunter.io/ios/app/slackwater-tides-and-currents/id6813654837/reviews)** |
| Number of ratings | **272** | 1 |
| Positive reviews | 56.8% of reviews | **100.0% of reviews** |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Monthly | Monthly |
| Monetization | Free with in-app purchases | Free with in-app purchases |
| Best chart rank | **#70** | — |
| Size | 50 MB | 59 MB |
| Requires iOS | **16.0** | 26.0 |
| Devices | iPhone, iPad | **iPhone, iPad, Apple Watch** |
| Age rating | 4+ | 4+ |
| Developer | [PredictWind Limited](https://appshunter.io/developer/477048590) | [Open Water Software LLC](https://appshunter.io/developer/1887683238) |

## What reviewers say

### PredictCurrent

[App page](https://appshunter.io/ios/app/predictcurrent/id6468610449)

**Currently charting:** #70 Top Grossing · Weather (US App Store)

Navigate coastal waters with detailed tidal and ocean current maps. Access 10-day forecasts for currents, wind, waves, and sea temperatures. Essential for safe marine planning and exploration.

**Highlights:** Ultra-high-resolution 100m tidal current maps, 400m and 4km global coastline coverage, 10-day animated forecasts for currents, wind, and waves, Hourly tide chart data, Wind-against-current interaction analysis, Sea temperature tracking

**Features:** Vision Pro support

**In-app purchases (5)**

| Purchase | Price | Billing |
| --- | --- | --- |
| PredictCurrent Pro 1-Month | $15.00 | per month |
| PredictCurrent Pro 3-Monthly | $29.00 | per 3 months |
| PredictCurrent Pro 3-Monthly | $29.00 | per 3 months |
| PredictCurrent Pro 3-Monthly | $29.00 | per 3 months |
| PredictCurrent Pro Annual | $99.00 | per year |

**What reviewers like**

- 📊 Detailed hour-by-hour current visualizations
- 🎯 Accurate tidal and current predictions
- 👍 Intuitive and user-friendly interface
- 🌊 Comprehensive water condition data (wind, tide, waves, temperature)
- 💼 Valuable competitive advantage for water sports professionals

**What reviewers complain about**

- 💰 Expensive subscription pricing ($24-30 quarterly)
- 🚫 Mandatory account creation required
- 📍 Limited geographic coverage and location availability
- ⏰ Forecast data limited to short timeframes (until 11am-noon next day)
- 🔐 Privacy concerns regarding personal data collection

**Reported bugs**

- Unable to add location error messages despite valid coordinates
- Location setup fails to respond or complete
- Password not saved correctly in database, preventing login
- Account creation fails with character handling errors
- App crashes when setting locations

**Requested features**

- Extended forecast data for full 24-hour next day coverage
- Smaller time increment stepping (sub-hourly) for racing
- Exact tide turn time information beyond hourly data
- Legend/symbol guide for app indicators
- Improved coastal and estuarine modeling


### Slackwater

[App page](https://appshunter.io/ios/app/slackwater-tides-and-currents/id6813654837)

This app provides tide and current predictions that work offline, even without a signal. It offers detailed information on tide times, current speeds and directions, and celestial events for thousands of stations worldwide. Users can access this data on their iPhone, iPad, and Apple Watch.

**Highlights:** Offline tide and current data, Tide predictions for 5,000+ stations, Current speed and direction, Sunrise, sunset, and moon phase, Apple Watch app and widgets, Siri integration

**Features:** macOS Compatibility, Family Sharing, Apple Watch app, Vision Pro support, iPhone Duo support

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Premium Yearly | $7.99 | per year |
| Premium Lifetime | $69.99 | one-time |


## Frequently asked questions

### Is PredictCurrent free?

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

### Is Slackwater free?

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

### Which has better reviews, PredictCurrent or Slackwater?

Slackwater is rated higher. PredictCurrent averages 4.5 out of 5 from 272 ratings, while Slackwater averages 5.0 from 1 ratings.

### Do PredictCurrent or Slackwater have ads?

Neither PredictCurrent nor Slackwater shows ads.

### Which is updated more often, PredictCurrent or Slackwater?

PredictCurrent ships an update monthly, and Slackwater monthly. Most recently, PredictCurrent was updated on November 12, 2026 and Slackwater on November 11, 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.*