NavList:

In my experience, it is the captain's call when to change the clocks.  As long as you arrive at your next port at the correct local time, he has wide leeway.  I have seen delayed or accelerated time changes to fit his traffic sending schedule (he doesn't want to get up early or stay up late) so we are far away from our time meridian (like taking LAN around 1400).

 

The tide tables are where you have to watch your DST as Greg mentioned.  That is the only place where I have had to think about it in navigation.

 

Jeremy

 

Alan,

At sea it is standard practice to stay on the zone time that is within 7* 30' longitude or less of the nearest zone meridian. This makes figuring sunrise, sunset, civil twilight, and LAN within 30 minutes of the NA listed time. Figuring the actual time for NA time listings requires an arc to time correction from the DR longitude to the zone meridian. Also be aware that most tide tables use standard time so an hour has to be added to get to daylight time.

Greg Rudzinski
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