Change orientation of watermark on one page ONLY

[J9]

I am producing a 100-page Word document with only one page in landscape
orientation. I want to change the orientation of the watermark for this page
only, so the final document will look the same. How do I do this?

 

[Suzanne S. Barnhill]

I would guess this will be a sort of variation on the "Portrait
header/footer on a landscape page" problem. See
http://word.mvps.org/FAQs/Formatting/LandscapeSection.htm