The basic fact of the matter is that if they are letting white kids in to swim but not black kids, then they are repugnant and do not deserve to draw a paycheck. Hopefully, there’s a way to get them out of their positions. If this story is true, I hope the people in charge eventually see the error of their ways. Racism is disgusting.
I understand you find racism repugnant. Most reasonable people do, however that doesn’t mean you can run over those peoples rights by claiming moral authority.
Extending this repugnance to claiming they have no right to draw a paycheck is where you lose any sort of defensible ground.
Yes, you have a right to be offended by it, and you can work to change the clubs policies/mind. However they do have every right to rebuff your efforts and continue in their actions.
They have the right to associate with whoever they want and not associate with whoever they want, and have the right to allow or disallow whoever they want from using their property for whatever reason they decide.
You can disagree with their decisions, but when you or others claim they should not have the right to make those decisions, or should be punished by government for them, you advocate tyranny not liberty.