Righting device for a water vessel

A device for righting a boat or other water vessel following a capsize, the device comprising an inflatable body adapted to be stowed in a collapsed state when un-inflated, the inflatable body being provided with or adapted for connection to a source of compressed gas for inflating the body following a capsize and comprising a flexible skin forming first and second inflatable chambers, the device further comprising a valve arrangement for causing the chambers to inflate in a predetermined sequence in which the first chamber is inflated before the second, the first chamber being provided with means for securely mounting it upon the vessel whereas the second chamber is coupled to the first chamber and is arranged, when the body is inflated, to be supported by it, so that due to its buoyancy the second chamber is able to apply a righting moment which is transmitted through the first chamber to right the vessel, and wherein when the inflatable body is inflated and the vessel is right way up, the second inflatable chamber is disposed above the first inflatable chamber.