Skysail

A skysail is the uppermost sail in many old square-rigged sail-plans (though sometimes topped by a moonsail). It was also on the royal mast above the royal sail. It was typically used in light winds.^[1]

The highest sail is moonraker, lower skysail and royal sail.
Skysail is the highest on the main (middle) mast.

References

^ King, Dean (2000). A Sea of Words (3 ed.). Henry Holt. p. 404. ISBN 978-0-8050-6615-9.

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[king404-1] King, Dean (2000). A Sea of Words (3 ed.). Henry Holt. p. 404. ISBN 978-0-8050-6615-9.

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