Boatnumberplate.com Rigid Hull Plates . For fiberglass metal and PWC hulls these stick-on plates are the easy way to create a professional-looking registration number installation on your boat. To receive your plates all you need to do is purchase the pre-packaged code then go online and specify the registration number and the color black or white. Background for the registration number is clear so your boat s color shows through. 3 block-style letters are USCG legal. Not recommended for inflatable boats.