Monitor and Optimize Your Sails

Take a photo of the sail with your smartphone and let SailWatcher calculate the fundamental parameters such as camber, draft, cord, twist, entry angle, and exit angle. Join the beta on iOS now.

Harness the Potential of Your Sails.

Track the parameters of your sails directly in the application and monitor changes over time. SailWatcher provides a simple way to maintain an accurate record of your sail settings, allowing you to optimize your boat's performance.

SailWatcher Engine

An algorithm has been developed that, requiring only a few pieces of information from the user, identifies and evaluates the sail shape lines, returning draft, camber, twist, entry, and exit angles.

Linea #1
Camber: 6.68%Draft: 36.21%Entry Angle: 11.32°Exit Angle: 15.71°Twist Angle: -4.67°
Linea #2

Frequently Asked Questions

If you have other questions about SailWatcher contact us at

What parameters does it calculate?

SailWatcher calculates the following parameters: camber, draft, twist angle, entry angle, exit angle. It also saves the boat's speed at the time of taking the photo.

Which devices is it compatible with?

SailWatcher is compatible with Apple iPhone 8 and later. There is no plan for an Android version. A version for iPad is also planned.

Does it work on every sail?

SailWatcher calculates the parameters of all sails with highlighted shape lines. If your sails have highlighted shape lines, you can use SailWatcher.

Does it require an internet connection?

SailWatcher is designed to be used in open water, it does not require an internet connection, except for some secondary functions (e.g., sharing).

Can I share the obtained data?

Yes, through a unique URL. The web page will contain photos, shape lines with their parameters, additional data (wind speed, ...) and additional notes entered by the user. Here is an example.

The tool cannot retrieve the data

SailWatcher performs a series of calculations to identify shape lines. If you cannot retrieve the data from your sail, let us know. We will analyze the case and improve the algorithm to identify your sail as well.

No Cost

SailWatcher is free, no payment, subscription, or purchase of additional equipment is required.
All you need, in addition to a suitable sail, is a smartphone.

The SailWatcher Project

SailWatcher originated as a project within the ISISLab laboratory at the University of Salerno.