# AnchorChainCalculator — Safer at anchorage! > Calculates optimal anchor chain/rope length for safe anchoring based on physics. (iPhone/iPad app by Mathias Wagner.) - Source: https://appshunter.io/ios/app/anchorchaincalculator/id1533741243 (this page in markdown: same URL + `.md`) - Developer: [Mathias Wagner](https://appshunter.io/developer/1533741245) - Category: Utilities, Education - Price: $12.99 - Rating: 5.00/5 from 5 App Store ratings · 2 written reviews indexed - Age rating: 4+ - Requires: iOS 10.0 · 12 MB - Languages: American English, Danish, Dutch, French (France), German (Germany), Italian, Norwegian Bokmål, European Portuguese, European Spanish, Swedish and 1 more - Released: 2020-09-30 - Data updated: 2026-08-24 - Monetization: paid - User reviews in markdown: https://appshunter.io/ios/app/anchorchaincalculator/id1533741243/reviews.md ## What is AnchorChainCalculator? 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! ## Key features - 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 ## Recent user reviews (2 of 2) All indexed reviews: https://appshunter.io/ios/app/anchorchaincalculator/id1533741243/reviews.md ### 4/5 — Toller Inhalt, Design + Bedienung steigerungsfähig *2024-01-31* Ich bin gerade dabei, einen neuen Anker (Spade) und eine neue Kette zu kaufen. Ich kannte die App aus der Yacht schon, hatte mich aber nie intensiver damit auseinander gesetzt. Was soll ich sagen, tolle App. Es ist sehr aufschlussreich, mal mit verschiedenen Parametern herumzuspielen und es kommen oft erschreckend lange Kettenlängen heraus. Für mich war es beisp. hilfreich, verschiedene Stärken der Ankerketten, Wassertiefen, Windstärken und „Snubber“ auszuprobieren. Das ist alles fix auf Knopfdruck berechnet und sehr hilfreich. Die paar Euro für die Offline Version (App) sind gut angelegt, denn erstens muss solche Mühe und Know How des Entwicklers auch vergütet werden und zweitens nutzt die Webbasierte Version nix, wenn man kein Netz am Ankerplatz hat. Stark verbesserungswürdig ist jedoch die Benutzeroberfläche und die (nicht intuitive) Bedienung. Für einige Funktionen ist es unabdingbar in die (sehr gute) Anleitung auf der Website des Entwicklers zu schauen. Das ist echt blöd und sollte bei dem Preis signifikant intuitiver und einfacher funktionieren. Wer sich vorher nicht damit beschäftigt hat, wird z.B. bestimmt daran scheitern, eine Kombi aus Ankerleine und Kettenvorläufer zu berechnen. Desdeweeschee nur 4 Sterne, sonst wären es 5 gewesen. **Developer response:** Danke für diese Rückmeldung! Und ja, die Benutzeroberfläche ist sicherlich nicht ganz intuitiv, diese Rückmeldung habe ich schon auf mehreren Wegen bekommen. Ich habe die meiste Zeit in die zugrunde liegende Physik und Mathematik gesteckt. Die eingebaute numerische "Engine" ist sehr robust und alles andere als trivial, da steckt viel Know-how drin. Das ist meine Kernkompetenz, und das macht mir Spaß. Ich bin jedoch kein professioneller App-Entwickler, der diese App Oberflächen optimal baut. Nicht mein Ding fürchte ich. Man kann sich immer streiten, was man für einen gegebenen Preis von einem Produkt erwarten kann. Wenn ich die gesamten Einnahmen durch die von mir investierte Zeit dividiere, kommt eine Zahl weit unter dem deutschen Mindestlohn raus, und das wird sich auf absehbare Zeit auch nicht ändern. Es ist also ein Hobby von mir und der Versuch, das Ankern etwas sicherer zu machen für uns alle. ### 4/5 — Good app *2023-05-10* Can I suggest the bow swinging circle isn’t a very useful measure. It would be ideal to easily calculate the radius from the anchor to the aft end of the boat, ie do the Pythagorean calc using the chain length and the depth to get the distance along the bottom and then add the boat length. That’s the number we need to plug into our anchor alarm app for our max safe swinging distance including the boat. ## Frequently asked questions about AnchorChainCalculator ### How does AnchorChainCalculator determine the correct chain length? AnchorChainCalculator uses physics-based calculations, considering vessel characteristics, water depth, swell, and wind strength to determine the optimal chain or rope length for secure anchoring. It moves beyond generic scope ratios to provide tailored safety advice. ### Can AnchorChainCalculator handle mixed rope and chain setups? Yes, AnchorChainCalculator supports arbitrary mixes of rope and chain, and can even calculate requirements for rope-only setups. This flexibility ensures accurate calculations regardless of your anchoring gear. ### What units does AnchorChainCalculator support? AnchorChainCalculator offers support for both metric units (metres, daN/kp, mm) and imperial units (feet, lbs, inch). This allows users worldwide to utilize the app with their preferred measurement system. ### How does AnchorChainCalculator compare to generic anchoring advice? Generic advice often relies on simple scope ratios (e.g., 3:1, 5:1) that don't account for specific vessel details or dynamic conditions. AnchorChainCalculator provides a more precise, physics-driven approach tailored to your unique situation. ### Can I save different boat configurations in AnchorChainCalculator? Yes, you can store multiple vessel configurations by name, allowing you to easily switch between different setups for various scenarios, such as different snubbers or vessel types. These configurations can be locked to prevent accidental changes. ### Does AnchorChainCalculator have ads? No, AnchorChainCalculator does not contain advertisements. As a paid application, it provides an uninterrupted user experience focused on its utility. ### What is the price of AnchorChainCalculator? AnchorChainCalculator is available for a one-time purchase of $12.99. This grants you full access to all its features without any recurring fees. ### How often is AnchorChainCalculator updated? AnchorChainCalculator was last updated on April 4, 2024, with version 2.2.8. This indicates a commitment to ongoing development and improvements. ## Version history (last 5 releases) ### 2.2.8 — 2024-04-04 Corrected bug in mixed mode chain and rope when swell energy is zero ### 2.2.7 — 2023-12-17 Improved offline help ### 2.2.6 — 2023-08-29 Quickly see what happens to your anchor setup when you increase the wind strength in steps of 5 kn ### 2.2.4 — 2023-08-21 Seabed slope can now be provided as angle or as gradient. Made chain and rope view interfaces more consistent with each other. ### 2.2.3 — 2023-08-16 More robust calculation. 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