Hi Doug.But, this raises a question in my mind. Many decades ago, navy ships manually plotted on paper courses of other ships in the vicinity, using radar ranges and bearings, and continuously calculated the time, range, and bearing of the predicted closest point of approach. The OOD and the bridge watch would keep an an eye on other ships with a close CPA, visually check their side and range lights, check the bridge radar, check bearings with the pelorus to make sure they were drifting away nicely, and make sure that updated CPAs were passed along to the bridge from the plotting below. Do I understand that this is now all done automatically by computers?
The commanding officer would leave instructions in the night order book specifying the circumstances when he must be awakened and summoned to the bridge. One such situation would be if the CPA of another ship is computed to be less than a specified distance.