Yes. In current Darktable versions, the practical way is to create a style from a history entry where the watermark module is turned off, then apply that style during export.

Workflow:

1. Open an image that currently has a watermark.
2. In Darkroom, disable the watermark module.
3. In the History Stack, create a style using only that watermark step.
4. Save it as something like "watermark off".
5. In Lighttable > Export, choose that style before exporting. You can also save this as an export preset.

This works because the style adds a history step that disables the watermark. An older workaround was to append a "watermark off" style before export and then undo it afterward, but using the export style/preset is cleaner.

One caveat noted by users: styles apply their recorded module state, so if your watermark settings were changed manually, the style may restore the saved watermark state rather than your latest ad hoc settings.