It seems you can have the Taraibune experience at Ogi Harbor or Yajima-Kyojima. https://en.japantravel.com/niigata/tarai-bune-in-ogi-town-sado-island/2465
My family and I will be visiting Sado Island, mainly for me to participate in the triathlon. My children want to try get on the Taraibune boat as it looks like fun. Where can we try that?