I cropped the image down to the banner, used the perspective tool so that the letters were the right shape, and was able to identify the club by reverse-image searching the flag alone. But I don't want to spoil the game, if this is considered cheating.
Mumbles Yacht Club! Well done, and thank you - I did not know! The hat says MUAYC and for those in the know... know that MUAYC has more to do with BAYC (bored ape yacht club) than anything in IRL ( in real life).