Originally Posted by JonEisberg
Well, to conserve power, perhaps? :-)
If you haven't the power to run your chartplotter with all the handy dandy features on it, that aren't just for show by the way, for the duration of your voyage, perhaps your power situation should be looked at. With the inexpensive windgens and solar systems on the market today, "conserve(ing) power" for your chartplotter should not be a major concern. Running lights now eat a tiny bit of electricity compared to a few years ago, probably saving what a modern chartplotter uses.
Little changes in speed, course and/or VMG which can't be seen without the constant use of the equipment, can alert the navigator to a developing situation, long before it becomes critical. I can see a ship when it gets close enough to be a danger, but a set beginning to push me into a rocky shore, perhaps not quite as easily, especially at night. No thanks, I'll take the chartplotter over the AIS.