The invention relates to an integrated circuit provided with a set of contacts for connecting the integrated circuit to a differential transmission line. The interface circuit provides wider bandwidth internal communications than external data transfers. The method encodes the pictures by the coding order when there are not scenes changed and encodes the pictures by a special coding process when there are scenes changed. The clamping device is mounted with the channel oriented horizontally and transverse to the fore-and-aft axis of the watercraft, with the slot disposed along a longitudinal side of the channel to allow insertion and removal the paddle shaft by fore-and-aft motion.