A route is only as good as the boat model driving it. There are two ways to supply one.
ORC certificate
Search by sail number or boat name and the certificate's performance table comes with it. This is the easier path and the more defensible one, because the numbers come from a rating authority rather than from optimism.
Certificate data is refreshed periodically. A certificate issued in the last few days may not have been pulled yet; paste a polar in the meantime and tell me which one is missing.
Custom polar
Paste a polar table. Rows are true wind speeds, columns are true wind angles, cells are boat speed in knots. Most formats that come out of a rating or logging system parse without editing. Warnings are reported rather than silently corrected — a polar with a gap in it produces a route with a gap in its reasoning.
Pasted and saved polars
A pasted polar is ephemeral by default. It travels inside the route request, stays in the current tab while you work, and is not written to the account. Reloading means pasting it again.
If you are signed in, Save polar is an explicit exception. It stores the accepted source text privately on your account so you can reload it and use it for a saved boat or sail. Saved polars are not shared with project members, used for analytics, or exposed by a route link. You can replace or delete one from the boat panel.
Routes record which performance data was used, but not the speed table itself. A collaborator may compute with a boat you lend to a project, but cannot read the polar behind it.
Sail inventories
A saved boat can also carry the sails that are actually aboard. Each sail has a wind envelope and may point to its own saved polar. With Route with the sail locker enabled, the search chooses among those sails and charges time for changes. See Sail inventory and crossover chart.