A mariner's cap, variations of which are known as skipper cap, Greek fisherman's cap, fiddler cap or Breton cap, Lenin cap and Mao cap, is a soft, flat-topped cap with a small visor, usually made from black or navy blue wool felt, but also occasionally from corduroy or blue denim. It is distinguished from similar caps, such as the peaked cap and maciejówka, by its soft, unstructured crown. It is often associated with seamanship and maritime settings, especially fishing, yachting and recreational sailing. It has become popular amongst the public in general, rather than staying isolated as an occupational hat. One example of it being put in prominence in popular culture was when it was worn by John Lennon during the British Invasion of the mid-1960s.