AnchorChainCalculator vs PredictWind Tracker
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
AnchorChainCalculator
Calculate the optimal amount of anchor chain or rope for secure anchoring based on vessel characteristics and sea conditions. Provides detailed load calculations and accounts for dynamic effects like swell and gusts. Supports both metric and imperial units, with options for chain-only or mixed rope/chain setups.
- Physics-based anchoring calculations
- Customizable vessel and sea conditions
- Chain-only or mixed rope/chain support
- Load and swell absorption analysis
- Metric and imperial unit support
- Multiple vessel configuration storage
- Basic and Expert modes
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Rather than following generic and unspecific advice how much chain or rope to pay out when at anchor, use this app to calculate the right amount of chain or rope needed for the anchor to have the best possible grip – safety tailored for your vessel! This app has been developed by a sailor living at anchor. It is based on physics rather than rules. Only too often does anchoring advice boil down to: Use a scope (i.e. ratio of chain length to water depth) of 3:1 in calm weather, and increase this to 5:1 or 7:1 as the wind picks up. This advice is independent of your vessel’s characteristics, independent of water depth, swell, or even the wind strength. So, is a scope of 7:1 still good enough for the storm tonight? Is the snubber or bridle you are using good enough to keep you safe at anchor? The Anchor Chain Calculator allows you to calculate the minimally required anchor chain and/or rope length based on a number of vessel characteristics and sea / weather conditions. It tells you what load the anchor will have to bear, and when you are using a snubber, bridle or rope, how much of the swell it absorbs, and how much it reduces the anchor load. When anchoring in shallow water it is particularly important to include these dynamic and elastic effects caused by strong swell and gusts. The app can work with a chain-only scenario as well as with an arbitrary mix of rope and chain. So, despite its name, it can also deal with a rope without any chain at all. ;) You can also restrict the chain or rope length, if you have to - perhaps because of nearby neighbours or obstacles - and get information how this restriction affects the anchor load and the angle at which the chain pulls at the anchor. The app has two modes of working: Basic Mode and Expert Mode. With Basic Mode you will be able to use the app right away, whilst Expert Mode allows you to enter more technical details of your boat if you know them. You can use either metric units (metres, daN / kp, and mm for chain thickness) or imperial units (feet, lbs, and inch for chain thickness). You can store different vessel configurations by name and so can easily switch, e.g., between different snubber, bridle, rope or vessel setups (e.g., a snubber for the lunch stop, another snubber for normal usage, and a third longer and even more elastic snubber for really bad weather). These setups can be locked to prevent accidental overwriting. This app is also great for playing through all kinds of "what if?” scenarios. It will help you to plan ahead and be better prepared. The perfect addition to an anchor alarm / anchor watch for safer anchoring!
PredictWind Tracker
Automatically update your personalized GPS tracking page for real-time location sharing. Ideal for boaters, it allows friends and family to monitor your position and route with weather or satellite maps. Link to add blogs and videos for a permanent record of your journey.
- Automatic GPS tracking updates
- Real-time location sharing
- Weather and satellite map overlays
- Add blogs and video links
- Personalized tracking page
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This app is designed to automatically update your personalized PredictWind GPS tracking page, ideal for Starlink users or those on LTE/cellular connections. Record and share your tracks to friends families and followers so they monitor your boats position and route in real time with weather or satellite maps. Link through to add blogs, video links for a permanent record of your journey. Note: You need a PredictWind GPS tracking page to use this app. To set up a PredictWind GPS tracking page contact https://www.predictwind.com/contact-us Terms & Conditions: https://www.predictwind.com/about-us/terms-and-conditions Privacy Policy: https://www.predictwind.com/about-us/privacy-policy
Screenshots
Verdict
The clearest difference is review sentiment: AnchorChainCalculator at 100% against PredictWind Tracker's 0%. AnchorChainCalculator also leads on rating (5.0 vs 4.4) and in-app purchases (none vs 3). PredictWind Tracker's advantage is price (Free vs $12.99). On ratings volume, ads and device support there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
PredictWind Tracker is free to download; AnchorChainCalculator costs $12.99 up front. PredictWind Tracker sells 3 in-app purchases, starting at $49.00 per month. AnchorChainCalculator asks for nothing beyond the download.
AnchorChainCalculator holds the better App Store score, 5.0 against 4.4. Both are backed by a comparable volume of ratings — 5 and 7 respectively. Written reviews point the same way: 100% of AnchorChainCalculator's written reviews are positive against 0% of PredictWind Tracker's.
AnchorChainCalculator ships an update every 3 weeks, PredictWind Tracker every 2 months. The most recent releases landed on October 8, 2026 and October 5, 2026 respectively.
| Parameter | AnchorChainCalculator | PredictWind Tracker |
|---|---|---|
| Price | $12.99 | Free — better |
| Rating | 5.0 (5 ratings) — better | 4.4 (7 ratings) |
| Positive reviews | 100.0% of reviews — better | 0.0% of reviews |
| Number of ratings | 5 | 7 — better |
| Update frequency | Every 3 weeks — better | Every 2 months |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Monetization | Paid | Free with in-app purchases — better |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 10.0 — better | 15.0 |
| Further details — not scored | ||
| Size | 12 MB | 88 MB |
| Age rating | 4+ | 4+ |
| Developer | Mathias Wagner | PredictWind Limited |
Customer experience
AnchorChainCalculator
PredictWind Tracker
In-app purchases
AnchorChainCalculator
No in-app purchases
PredictWind Tracker
- PredictWind Tracker 1 Month7 Days trial$49.001 Month
- PredictWind Tracker 3 Months7 Days trial$99.003 Months
- PredictWind Tracker 12 Months7 Days trial$249.001 Year
Questions
Is AnchorChainCalculator free?
Is PredictWind Tracker free?
Which has better reviews, AnchorChainCalculator or PredictWind Tracker?
Do AnchorChainCalculator or PredictWind Tracker have ads?
Which is updated more often, AnchorChainCalculator or PredictWind Tracker?
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