AnchorChainCalculator 4+

anchor safely in storm

Mathias Wagner

Designed for iPad

    • $7.99



Safer at anchorage! Calculates required minimal anchor chain length/ anchor load.

The perfect addition to an anchor alarm / anchor watch for safer anchoring!

Rather than following generic and unspecific advice how much chain to pay out when at anchor, use this app to calculate the amount of chain needed for the anchor to have the best possible grip - safety tailored for your vessel!

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 / bridle good enough to do the job?

The Anchor Chain Calculator allows you to calculate the minimally required anchor chain 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, how much of the swell it absorbs, and how much it reduces the anchor load.

You can also restrict the chain 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.

You can store different vessel configurations by name and so can easily switch, e.g., between different snubber/bridle or vessel setups. These setups can be locked to prevent accidental overwriting.

The perfect addition to an anchor alarm / anchor watch for safer anchoring!

What’s New

Version 1.7.1

Updated French and Danish online help

App Privacy

The developer, Mathias Wagner, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy.

Data Not Collected

The developer does not collect any data from this app.

Privacy practices may vary, for example, based on the features you use or your age. Learn More


  • Family Sharing

    Up to six family members can use this app with Family Sharing enabled.

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