Re-worked for 2014, our Chronometer Rate Journal "Tyma" log book now has a new design, including numbered pages.Centuries ago the Chronometer allowed the Navigator to determine the vessels Longitude through accurate measurement of time. In today’s modern world accurate time keeping is still essential and a precise Chronometer is still required for Celestial navigation, which remains one of the competency requirements for Bridge watchkeeping officers.The modern marine Chronometer may be based on quartz clocks periodically corrected by GPS signals to maintain accuracy but every Navigator knows GPS signals are prone to blocking or even loss of signal. Thus it is logical that the prudent Navigator should rate the ships Chronometer on a regular basis. Brown’s Chronometer Rate Journal "Tyma" allows the modern Navigator to monitor the accuracy of the ships Chronometer throughout the voyage.
