minimum weight for coxswains is 55 kilograms (121.25 pounds) in racing uniform. If a cox is underweight they are required to make up the weight with a deadweight up to a maximum of 15 kg, and the deadweight must be carried as close as possible to the cox (usually a sandbag). Articles of racing equipment (e.g. cox boxes, water bottles) cannot be considered as part of the deadweight. Similar deadweight rules are used in the United States. Cox box Coxes in all boats can use a cox box, most models of which show the rate in strokes per minute of the person sitting in the stroke seat (the seat at the rear of the boat, from whom the rate of strokes per minute and timing is taken). Additional features include: a stopwatch started automatically at the first full stroke stroke ratings over time GPS speed measurement Ratio of the power phase to recovery (speed of oars through the water versus returning out of the water for the next stroke) 500 meter split times Stroke count Metronome for stroke rates However the primary function of a cox box is to amplify the coxswain's voice, using a microphone connected to loudspeakers in the boat. This means that the cox needs only to speak for all rowers to hear their voice. For an eight-man crew three or four speakers are set down the length of the boat; for a four-man crew two speakers are used. Pairs may not have speakers if coxed from the stern but will have one if coxed from the bow (in front of the rowers). Historically the cox would have carried (or strapped to their head) a conical, unpowered megaphone to amplify their voice. Notes References Further reading Various Authors. Boys' Life, 1933 — Further information on the role of the Coxswain. Rowing positions