The present invention relates to a new and useful improvement in the field of sport fishing whereby a sinker that is commonly used for casting purposes is improved upon by allowing the weight component of the sinker to be removed or exchanged for weights of different mass without damage to the line or weight. The invention eliminates the time consuming steps commonly associated with salvaging the fishing line or weight during removal, exchange, and provides an inexpensive releasing device when the sinker becomes irretrievably snagged on a submerged object.