double and triple buckets are possible (variants also known as German rigged, Italian rigged or tandem-rigged). Canvas The deck of the bow and stern of the boat, which were traditionally covered with canvas. Cleaver blade Modern oar blades that have a more rectangular hatchet-shape. (also hatchet blade) Collar / Button A wide plastic ring placed around the sleeve of an oar. The button stops the oar from slipping through the oarlock. Cox box Portable voice amplifier; may also optionally incorporate digital readouts displaying stroke rate, boat speed and times. Coxmate A portable amplification device, similar to a coxbox, incorporating a digital readout. Higher-end models may also have a built in radio and speed sensor. Empacher slot A UK term for the clip at the on the top of the bow for holding racing number plates. Ergometer (also ergo or erg) An indoor rowing machine. Foot stretcher An adjustable footplate, to which a pair of shoes is typically attached, which allows the rower to easily adjust their physical position relative to the slide and the oarlock. The footplate can be moved (or "stretched") either closer to or farther away from the slide frontstops. (also "Footplate", "Footchock", "Footstop", or "Stretcher") Frontstop The stop mechanism on the seat slides which prevents the rower's seat from falling off the sliding tracks at the front end (towards the boat's stern) of the slide tracks. Also, in the UK, the sliding seat position closest to the boat's stern. As a command, it instructs the crew to adopt this position. (The US calls this seat position the "front end") Gate (UK) Bar across the top of rowlock, secured with a nut, which prevents the oar from coming out of the rowlock. Also historically used to refer to the oarlock or rowlock. Swivel (US) Gunwales (pronounced: gunnels) The top rail of the shell (also called Saxboard) Handle The part of the oar that the rowers hold and pull with during the stroke. Hatchet blade Modern oar blades that have a more rectangular hatchet-shape and which are not symmetrical. (also cleaver blade) Hull The actual body of the shell. Inboard The length of the oar shaft measured from the button (or from the pin) to the handle. Keelson A structure timber resembling the keel, but on the inside of the shell. Launch A motorboat used by rowing instructors, coaches or umpires. Referred to as a "coach boat" in Canada.