9 MEASURING, SIGNAL AND MONITORING MARINE INSTRUMENTS, NAMELY, SPEED AND TRIP COUNTERS, TRIMMING MEASUREMENT APPARATUS, SPEEDOMETERS, DEPTH SOUNDERS, COMPASSES, WIND MEASUREMENT APPARATUS, TACHOMETERS, PYROMETERS, FUEL GAUGE, FRESH WATER TANK GAUGE, LIQUID LEVEL GAUGES, PRESSURE GAUGES, TEMPERATURE GAUGES, AMMETERS, VOLTMETERS, RUDDER ANGLE INDICATORS, BAROMETERS AND HYGROMETERS