Just come across this as searching for waterproof switches etc. May be worth a look if your thinking of adding a USB port. Good thing about it is that it remains waterproof when in use, none of others I've seen do. Downside is finding a good location. If you had a good fairing with back access would be best as rear of unit still likely to get water on it otherwise. Still worth a look..https://www.furneauxriddall.com/acatalog/Scanstrut-ROKK-Charge+-Waterproof-USB-Socket--12-24V--SC_USB02.html#SID=421