The only thing we could spear in this hole is the jersey devil. As legend has it. I do think we should bring rope and chain for a decent and accent line. Tie off to a tree. If you read the myths not only is it bottomless but it is described as pulling swimmers down to it’s depths. If this is true I would translate this as being fed by another passage. If that is the case and if it is deep enough the flow could def drag you down. As for thermal protection. I own a cf200 so I surely will be diving it. If this hole is deep I will be bringing a set of double 108’s and a 100 percent oxygen deco bottle. There has to be a reason nobody has dived this hole before. And if they did why did nobody record it.