No, the USGC does not require you to wear a helmet. However, it's a good idea if you wear one, especially if you're kayaking alone. Kayaks don't have the same recognition as boats, so PFDs and helmets are not essential mandatory equipment. However, if you want to improve your chances of coming back from your kayaking trip, it's a good idea to kit yourself out with safety gear. While the USCG does not force people to wear helmets, it does certify certain helmet safety specifications.