the river an oil barge or other similar vessel 16 is moored to the dock 15 the apparatus or boom 10 for confining the oil or pollutants may be constructed of several materials and the design may be of several presently available as a series of hollow units or sections that are connected together to form a flexible elongated unit with spaced end portions 17 and 18 depending on the length of the sections and the form of the joint connecting the sections the confining apparatus or boom may have any desired configuration and size as an example a section of the boom 10 has a vertical dam 19 sandwiched between two d shaped hollow flotation elements generally designated 20 the overall width of each element 20 is one fourth to two thirds the overall height of the vertical dam 19 and greater than the height of the element itself the flotation elements 20 are substantially continuous along the full length of the barrier or boom 10 except that at the midpoint the joint or connection 21 between the sections has greater flexibility to allow the boom 10 to form a pair of flexible elongated body portions which may be in abutting relationship for a purpose to be described such joint or connection 21 may have a loop 22 molded therein fig3 to receive one end of a tow or holding line 23 suitable vertical plastic ribs 25 are located at suitable intervals along the length of the boom or barrier 10 the ribs 25 may be bonded sealed or otherwise fastened against the dam 19 and elements 20 in order to provide a semi rigid stiffener and body to the barrier or boom 10 the ribs.