Yes, riding sail
We made one from an old Bluejay sail. Hanks on to the backstay and the end of the boom. Works very well. However, in an anchorage where everybody else is swinging and you are not, there can be a problem if boats are too close to one another. You will be out of step.There was an article in Ocean Navigator recently about a disabled yacht being towed by another yacht in the Atlantic to Ireland. The major problem with the tow was that the towed vessel swung wildly from side to side, just like an unstable boat at anchor. But the photographs show the towed vessel with the jib partially unfurled, which I should think would guarantee that it would wildly swerve. I am puzzled as to why they did not rig a riding sail of some sort. I am sure it would have towed far more sedately