Today we were following the coast of Peru on a South Easterly course. The continent is starting to taper off now and will eventually end at the point of Cape Horn. With going more to the East you get the time changes. We gave one hour forward last night and there will be one more the coming night. That will bring the ships time to GMT – 3 hrs. or onto local Chilean time. GMT stands for Greenwich Mean Time and on that standard time the nautical world is based. In Greenwich is also the Zero meridian which divides West from East and from there we count minus hours to the West and plus hours to the East. The zero meridian was an artificial decision to sort out the world’s times issues. They could as well have chosen Amsterdam or Stockholm and for awhile the French had their own Zero meridian which of course ran over Paris. However the nautical world has settled on Greenwich and the shipping fraternity works with GMT.
If you make cruises around the world or with the Prinsendam where we are all over the place, you need a standard time to work with otherwise you run into all sorts of confusion. To give an example, when we go to Montevideo (GMT – 2hrs) later in the cruise, we will be going one hour forward after leaving Buenos Aires (GMT – 3 hrs). Then before arriving in Rio de Janeiro we will go back again an hour as Rio is on GMT – 3. A ship that would sail directly from BA to Rio would not do a time change at all while sailing through the same area. If you now would have to exchange time related messages with that particular ship you could get into a big time muddle about what the local time would be and by using GMT you avoid that all. This is one of the reasons why the world’s maritime weather forecasts are announced on the fixed times of 0600, 1200, 1800 and 2400 GMT.
For the guests onboard we do use local time as much as possible. As a result the sun keeps rising more or less at the same time and nobody has to think about ships time and local time when going ashore. I have done it occasionally that I stayed on ships time. If you have set the clocks forward the first night and then go back the second night that is too much change in a 24 hour period. You can also ignore the concept completely and stay on ships time the whole cruise. Several cruise ships in the Caribbean do this. On departure Miami it is announced that the ship will stay on Miami time and please look at your own watch only. As long as you have not left your watch on mountain – time or something else, you will be in good shape. However in general it works the best if you work with the ship on local time when in port.
When you have multiple time changes during a cruise, such as during a Trans Atlantic crossing, then there are a plethora of ways to do the changes. It is possible at 2 am. or at noon time or a 1 pm etc etc. One hour, during a few nights or 30 minutes each night; what ever works best. When I became captain I experimented a little bit with the various options and found that the time changes forward have the least impact if they were done at 1 pm. in the afternoon. You start the voice from the bridge at 1300 hrs. and you end the voice at 1405 hrs. It has the advantage that you can announce the time change at the same time when it happens. Everybody is awake, everybody is listening and everybody can right away adjust their wrist watch. When the clocks go forward (eastbound crossing) this works very well, you do not loose any sleeping time during the night and you do not feel compelled to retire early. Westbound (hours back) I keep doing the time change during the night, as it makes the evening longer and you can still catch a bit of extra sleep if wanted. At the same time it does not stretch lunch hour into a whole afternoon affair.
So we will arrive in Arica, Chile tomorrow morning at GMT – 3hrs. with a pilot time of 7 am. It is less then a mile to the dock and thus I should be alongside by 07.30. waiting for the authorities to clear the ship. The weather looks still good. Partly cloudy skies with temperatures in the low seventies around lunch time.