Abstract: A projectile (10) arranged to be launched from a launcher (12), the projectile comprising a source of compressed gas (1) and control means (23) for controlling the release of the compressed gas, in which the control means (24) is arranged so as to release the compressed gas in response to the launching of the projectile (10) from the launcher (12). Typically, the control means (24) is a valve, arranged such that the application of gas pressure from the launcher (12) is required in order to release the compressed gas, but the application of gas pressure must abate before the compressed gas is released. Thus, the compressed gas may only be released once the projectile (10) has cleared the launcher (12).

Abstract: An inflatable boom (1), the boom being elongate and being provided with at least one line (4) by means of which the boom can be launched from a watercraft into surrounding water. Typically, the boom would be launched into the water by means of a compressed gas launcher (6) launching a projectile (5) on the end of the line. The inflated boom (1) can be used for lifesaving operations to rescue a man overboard (10), or for the recovery of oil spills on water. Also, the boom may be provided with a light source (15), typically internal to the boom (1), with windows (19) along the length of the boom (1) allowing light transmission from the internal light source (15). To this end, the internal wall (20) of the boom may be reflective.