An oil boom has a longitudinal hose-shaped floating body of cloth or fabric material, and a skirt, also of cloth or fabric material, extending from the floating body and equipped with sinkers. The floating body has internal inflatable hoses serving as distension elements. The inflatable hoses are fixed to the floating body and, in their inflated state, they are ring-shaped and they lie substantially in planes which are perpendicular to the axis of the floating body to distend it into hose shape. The inflatable hoses have an air-proofing layer of elastomeric material and a reinforcing structure. The reinforcing structure includes a tensile-stress-absorbing inner reinforcing layer and a hose-expansion-limiting outer reinforcing layer. The inner reinforcing layer is formed of substantially parallel reinforcing threads extending in the longitudinal direction of the hose. The outer reinforcing layer includes two groups of reinforcing threads extending helically in opposite directions at an obtuse reinforcement angle to each other around the hose.