The polar is what Offwind expects the boat to do in each wind. On the phone it drives two things: routes worked out on board, and the live targets on deck, such as target boat speed, target angle and polar percentage. It is kept on the phone, so both work with no connection at all.
Open it from Boat, then Polars. The row shows the polar the boat sails with now, or None.
Get a polar onto the phone
There are two ways, and you can use both.
From your Offwind project. If the project is filed into a web project, choose the boat under the project's Boat section. Its polar or ORC certificate comes down to the phone by itself while you are signed in and online, and is kept for offline use. It appears under Server model. Press Check the server now to fetch a newer one at once.
From a file. Press Import a polar file… under Versions and choose the file. Offwind
reads the same formats as the website: Expedition, qtVlm, OpenCPN and B&G .pol grids, CSV or
tab-separated tables either way round, decimal commas, Expedition angle-speed pairs, and ORC
certificate JSON. A notice confirms what was imported.
Choose the one you sail with
The polar at the top, under Sails with, is the one routing and the deck use. To change it, open another version and press Sail with this polar. It is marked Active.
If the project's boat has sails listed, Sail polars lets you give a sail its own polar. A sail with its own polar uses it inside its wind range; the others use the boat's.
Scale and edit
Open a version to see its diagram and table.
- Performance. Step Performance up or down, then press Save at 95.0% as a new version. Every speed is scaled, as the website's performance percentage does. Use it to sail to a fouled bottom, a short-handed crew, or a cruising load.
- One speed. Press a speed in the table, type the new value, and press Save as new version.
- Rename… renames a version of your own. The server polar keeps its name.
Each change is saved as a new version. The one you started from is kept, so you can always go back.
Learned from the instruments
While you sail with instruments connected and a polar active, Offwind compares steady sailing with the polar, wind speed by wind angle. It never changes the polar by itself.
- Open the review. On Polars, press Learned from the instruments. Until there is enough steady sailing it reads Nothing to propose yet.
- Read the summary. Cells changed, Mean change and Largest say how far the boat has been from the polar, and over how many minutes of steady sailing.
- Choose how much to take. Slide Adopt from 0% (keep the polar) to 100% (take the speeds the boat actually did). Cells marked Weak need more sailing in that wind to be sure.
- Apply. Press Apply as a new version. Turn on Also save to my account first to keep it with your Offwind account too.
Share and keep
Under Share and remove in a version:
- Export… saves it as CSV (web, Expedition pairs), .pol grid (Expedition, qtVlm, B&G) or JSON.
- Save to my account copies it to your Offwind account, where it is marked In account.
- Delete version, held to confirm, removes a version you made. For the server polar the button is Remove from this device; it comes back the next time the boat is selected.
Limits
- A polar that belongs to another owner's boat can be sailed with but not exported or saved to your account. Its owner can see that this device holds it, and if they withdraw it, it and every version made from it are removed the next time the phone connects.
- Proposals need a few minutes of steady sailing in a given wind. Only steady sailing counts.