as illustrated in fig1 and 2 , the diving stick of the first preferred embodiment of the invention includes a generally cylindrical or elongated body 1 made of a material having sufficient softness and / or malleability to bend when it encounters a person so as 1 include soft polyvinyl chloride and rubber , although the invention is intended to encompass any material with similar properties of softness and malleability . body 1 of the diving stick is divided into two sections or chambers 2 and 3 , which may be separated from each other by an inwardly extending flange 4 . chamber 2 is arranged to hold a weight 5 and includes an end cap 6 that enables removal of the weight , although those skilled in the art will appreciate that the weight 5 may instead be permanently enclosed within the chamber and the end cap replaced by an end wall of the body 1 . the weight 5 , may for example be of the approximate size and weight of a { fraction ( 3 / 16 )}″× ½ ″ bolt and nut , although the configuration of the weight may be varied depending on the size and desired sink rate of the stick . in order for the diving stick of this embodiment to work , however , the weight must be confined to the end portion of the stick represented by chamber 2 . chamber 3 includes at least two openings , one at each end , to permit flow of air and water . in particular , opening 7 , which is the opening closest to divider 4 of the illustrated embodiment , is arranged to permit ingress of water while openings 8 , of which there are three in the illustrated embodiment are arranged to vent air as water flows into openings 8 . as a result , when the diving stick of this embodiment is initially tossed into a swimming pool or other body of water , it will initially float in a horizontal orientation . because one end is weighted , the end of the diving stick containing the weight will dip sufficiently into the water to cause water to begin to enter opening 7 , as illustrated in fig3 a . as water enters opening 7 , air will be expelled through openings 8 , as illustrated in fig3 b , causing the stick to be filled with water up to the level of the closest of openings 8 to the end of the stick opposite to the weighted end . however , a pocket of air will remain trapped in the end portion of chamber 3 , which will cause the stick to maintain an upright orientation as it sinks and comes to rest on the bottom of the pool , as illustrated in fig3 c . once the diving stick is retrieved from the bottom of the pool , the water will flow out through openings 7 and 8 and the stick will be ready for re - use . in the embodiment illustrated in fig4 the diving stick includes an elongated soft body 10 made of a natural or synthetic , water permeable , cloth or fabric material such as polyester or nylon , filled with a soft stuffing material such as foam or polyfill 11 . again , the invention is intended to encompass any materials having properties of softness and pliability corresponding to the described materials , with softness and pliability being defined by the lack of potential for impalement or serious injury to a diver . in this embodiment , the weight is provided by a mesh or cloth sack 12 filled with sand 13 or a similar material will cause the stick to have a preferred orientation as it sinks . the enlarged end 14 opposite the weighted end helps the stick of this embodiment maintain an upright posture by serving as a reservoir for air trapped in the polyfill stuffing material as water is absorbed through the cloth outer layer 10 . in a modification of this embodiment of the invention , the fabric and polyfill construction of the stick illustrated in fig4 may be replaced by a tube of woven material 15 , as shown in fig5 that is stiff enough to maintain a generally cylindrical shape without stuffing , and that has a weighted end 16 so that the specific gravity of the tube at the weighted end is greater than 1 . this type of tube will sink in the same manner as the conventional diving tube as water enters the tube through the woven material or through openings in the tube , and may optionally include provision for an air pocket at the top to help maintain the upright posture . the material in question is often used in lawn furniture , and also in a novelty device known as the lawyer &# 39 ; s handcuff . although various preferred embodiments of the invention have been described with sufficient particularity to enable a person skilled in the art to make and use the invention without undue experimentation , it will be appreciated that numerous other variations and modifications of the illustrated embodiments , in addition to those already noted above , may be made by those skilled in the art . for example , the diving stick may have a shape other than the generally cylindrical shapes illustrated in the drawings , so long as the sticks are generally elongated so as to have a preferred orientation and so long as the sticks can easily be grasped by a diver . in addition , it is possible that other ways of achieving negative buoyancy could be used without departing from the broadest principle of the invention , which is to make the diving sticks of a soft , malleable material in order to eliminate the risk of impalement . for example , although the illustrated embodiments use discrete weights , the illustrated diving sticks may utilize any construction in which one end has a specific gravity greater than 1 ( the specific gravity of water ) so that the stick will begin to sink and therefore take on enough water to bring the overall specific gravity of the stick to greater than one . each of these variations and modifications , including those not specifically mentioned herein , is intended to be included within the scope of the invention , and thus the description of the invention and the illustrations thereof are not to be taken as limiting , but rather it is intended that the invention should be defined solely by the appended claims .
a diving stick of the type which , after being tossed into a swimming pool , sinks to the bottom while maintaining an upright posture so that it can easily be grasped by a diver , includes a soft malleable outer body designed to prevent accidental impalement , and provisions for enabling the diving stick to sink and maintain an upright posture at the bottom of the pool despite the buoyancy of the soft malleable material .