Now to complete the look
Selections - INVERT
Click on the Fill Tool - Color (off to the Right) Click on Black
Then be sure to click on the bottom blank layer Fill with black
Move theOpacity down to barely visble about 10
You want to have the watermark just visable
Now Selections - Select None -
Right Click ON the top layer.
Merge - Merge Visible
Click on the Crop tool and surround your watermark.
Double click in the selection to crop.
Now Save as a png.
Png files can easily be converted to svg files.