That all depends on where you intend to charter. If you would like to charter a yacht within Europe, the answer would be yes. It is important to remember that the correct licencing and/or documentation for your charter is your responsibility and we would strongly advise you to enquire into the legal prerequisites of your chosen charter region, taking care to note any differences if you are to cross maritime boarders.
Regarding Europe, you will require an International Certificate of Competence, also known as the ICC.