Rate-of-Turn (ROT) Indicator
The ROT indicator shows the rate at which the vessel is turning, expressed in degrees per minute, and the direction of that turn. The OOW uses it during confined-water manoeuvring to anticipate swing before it becomes excessive — the display responds faster than the compass heading, so you can apply rudder to check a turn while there is still time. During watch-keeping in open water, a sudden ROT reading where none is commanded signals a possible steering failure or unexpected current. Always confirm the indicator is powered and reading zero on a steady heading before departure.
Course Recorder
The course recorder produces a continuous paper or electronic trace of the vessel's heading over time. Its value is twofold: it allows the OOW to monitor heading-keeping performance in real time, and it creates an objective record for post-incident investigation. Before handing over a watch, check the trace is running and the paper (if fitted) has sufficient roll remaining. An erratic trace during a steady passage is an early sign of autopilot or gyro malfunction and must be investigated and logged. Ensure the clock driving the recorder is synchronised with the vessel's bridge clock — discrepancies make any subsequent reconstruction unreliable.
Echo Sounder
The echo sounder measures depth of water beneath the transducer. The OOW must know the transducer depth below the waterline so that under-keel clearance can be calculated correctly — the instrument reads to the transducer, not to the keel. Set the shallow-water alarm to a value that gives meaningful warning ahead of the vessel reaching a critical depth, accounting for vessel speed and the rate of shoaling. Cross-reference soundings with the charted depth to detect strong tidal set or positional error. Verify the instrument is on the correct range scale; an inappropriate scale can make shallow water appear safe. Log any significant deviation between charted and observed depth.
NAVTEX
NAVTEX is the automated medium-frequency broadcast system that delivers navigational warnings, weather forecasts, and search-and-rescue information directly to the bridge printer without watchkeeper input. Each station and message category is identified by a letter code, allowing the receiver to filter irrelevant stations and suppress routine messages already received. The OOW must ensure the receiver is switched on and not incorrectly programmed to reject categories that are operationally important — navigational warnings (category B) and SAR information (category D) should never be suppressed. Check the paper roll or internal memory regularly; a receiver that is on but out of paper provides no watchkeeping benefit. All NAVTEX messages applicable to the planned route must be read, acted upon where necessary, and retained on board as part of the navigational record. Under SOLAS requirements (as applied to yachts through the applicable yacht code), carriage of a NAVTEX receiver is mandatory in sea areas where the service is provided.