Yes! If you'd like to turn your watermark on or off on a specific event, you can do so without disturbing your default settings for the rest of your events.
To do so, access your event in the Proofing control panel by clicking on the Proofing icon, then the Events tab, and clicking on the name of your event.
From there, click on the gear icon to access the event settings section.
Toward the bottom of the Event Settings page, you will see an option that reads Display Watermark. Select Yes to display the watermark or No to hide the watermark.
Make sure to click on save changes after you've made your selections.