When at sea, which time zone do ships use?


When travelling around the world by ship, it can become confusing what time it actually is. Are you in the same time zone as your departure port or your destination? In reality, ships follow their own unique time zone known as ship’s time, or nautical time.

The rationale behind this is that it makes communication between the captain, crew and officers simpler, especially when sailing across a vast ocean. Ships’ time is maintained through the use of a 24-hour clock, which is divided into six four-hour periods known as watches. This lets everyone onboard know when they are expected to be on duty, to have meals or when to relax.

Ships operating in different time zones around the world use Greenwich Mean Time (GMT) as the standard. This is an international time standard used by ships, airlines and many other industries to make sure everyone is on the same page. This means that ships effectively track two time zones – their current location and GMT.

When a ship crosses one time zone’s boundary line, the ship’s time is adjusted by one hour. This keeps the ship on track with the local time zones it is passing through. Unfortunately, this can mean that passengers onboard will experience losing or gaining an hour’s sleep in a single night as they adjust to the new ship’s time.

It is important to note that ship’s time is not always accurate to geographical time zones. This is because geographical time zones are often full-hour divisions, while ship’s time can include half-hour or even fifteen-minute increments. This makes it easier to keep track of watch rotations and other on-board schedules.

When at sea, ships use their own unique time standard “ships’ time”, which is based on GMT. This enables crew members to keep track of their watch schedules and other obligations onboard. It also simplifies communication between the captain and crew members on board and with those on land. So, the next time you’re on a cruise or travelling across the ocean, make sure you check the ship’s time before making any plans!

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