If you operate a yacht you will need a VHF Radio licence, training and a test if required.
Erith Yacht Club runs courses periodically, contact the Hon Sec on the contact form on the menu.
https://www.ofcom.org.uk/spectrum/radio-equipment/ships-radio
Training Course info from RYA
https://www.rya.org.uk/training/courses/marine-radio-short-range-certificate-course-srcc