Patent ID: 8920202

Claim:
A buoy, comprising: a first piece with a first cavity defined by a first sidewall, a first open end and a first closed end which is opposite to the first open end; a second piece having a second cavity defined by a second sidewall, a second open end and a second closed end which is opposite to the second open end; and a separation piece to separate the first cavity and the second cavity so as to form two separated watertight compartments, wherein the first sidewall includes a first portion, a second portion thinner than the first portion and defining a periphery of the first open end, and a shoulder between the first portion and the second portion, wherein the separation piece is a plate having a peripheral portion resting on the shoulder of the first sidewall, and wherein the second sidewall and the second portion of the first sidewall are fitted over each other and form a watertight joint therebetween.