In car wash there is not much of a cavern part kind of. Story tell people that venture into cavern are always attract to go a little bit further and venture into the darkness. Even in a cavern a silt out could happen and they could get lost. Someone could get a problem with equipment start to freak out among the other and not make it out. ok really now i am stopping!Not sure what single tank diving and no training has to do with OPs questions?
Every message OP sent is 100% clear that he is asking about the right way to do the dives he likes with this buddies.
And now we are saying that he should not dive in a CAVERN without a guide even if he completes full cave?
@mxdiver25 get full cave like @ginti recommended and you can dive every cavern you like for hours and have a humangous safety margin with two tanks