Yes. UM10, as leeward boat, has the right of way. UM8 is entitled to mark room - but not as much as she wants. Only enough to sail to the mark, and then room to sail her proper course while at the mark.

The funny thing was, UM8 left the mark with UM10 in her dirty air and beat UM10 in the race and the regatta. (The leeward mark they rounded was the last mark before finishing.) UM8 protested "as a matter of principle" and was convinced we had made an error in dismissing the protest - to the extent that she appealed the decision twice.