A rigid inflatable boat adapted for ease of lifesaving includes an arc-shaped front tube fixedly installed at a front side of a hull and a rear tube slideably installed at a rear side of the hull. A respective sliding rail having a guiding member disposed therein extends longitudinally on an upper surface of the hull at one or both sides thereof The rear tube is slideable forward and backward along the sliding rail due to the operation of the guiding member. A first holding means for detachably supporting a rear end of the arc-shaped tube and a front end of the rear tube is installed between the rear end of the arc-shaped tube and the front end of the rear tube. An open space between a rear end of the arc-shaped front tube and a front end of the rear tube provides ease of lifesaving.