that story have circulated for years, the problem is it evolves around a single oak tree off of the indian river in Delaware ,reportedly near "ware cove", that area has been developed and is infested with oak trees, so without more precise information, it is hopelessly lost forever. assuming one could get even close to the area, most accounts of captain kidds hidden treasures would have been buried several feet deep, making the average metal detector quite usless. a more effective tool would be a portable ground penetrating radar system, there is a good unit made by a german company but it is in the $17,000 to $20,000 range, but this would be usefull in locating those unusual square shapes underground at considerable depths
