▎ 摘　　要

NOVELTY - The buoy device (100) has a pair of cases (120) coupled to each other to form a hollow for generating buoyancy. A set of connection holes (140) is formed in a surface of the cases, and extended toward an end side of the case, and a set of reinforcing protrusions is protruded from an inner surface of each case and extending along an inner circumferential surface of the case to improve durability of the case. The case is made of synthetic polymer i.e. as polypropylene and graphene. Another set of connecting holes is arranged to face each other in pairs, and third set of projections is arranged inside the former set of projection. USE - Buoy device for use in fish farm used to mark area or location in farm, etc., or to prevent net from sinking underwater. ADVANTAGE - The device has better anti-fouling and anti-denaturation functions, and high durability against collisions or sea waves. DESCRIPTION OF DRAWING(S) - The drawing shows a perspective view of buoy device. 100Buoy device 120Case 122Coupling protrusion 140Connection hole