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Message: <blockquote data-quote="CarlZog" data-source="post: 2776048" data-attributes="member: 11716">Yes.A ship sailing offshore operates around the clock. A ship's crew is broken up into two or possibly three watch groups. Watches generally lasted four hours. Time is kept with sand hourglasses and bell is rung every half hour to signify the passing of time. (Ring once after the first half hour, twice after the second half hour, etc, 'til "eight bells" at the change of the watch.)Offshore navigation is mixture of dead reckoning and celestial determinations of latitude.Dead (from deduced) Reckoning is simply plotting the course you've traveled knowing the speed you're traveling and the direction (courtesy of your compass).Speed was checked every 1/2 hour with a chip log (A piece of wood attached to a rope is thrown over the side. You let out more rope as the ship sails away from the piece of wood. After a set amount of time -- noted on a small sand hourglass -- you reel in the rope and measure how much you let out. To help measurements the rope was knotted at set intervals, resulting in nautical speeds being referred to as "knots".)The mate in charge of the watch kept track of speed and direction every half hour on a pegboard known as a traverse board, and the captain or navigator would convert the info to a chart plot later.Latitude was determined by observations of the sun at noon or of polaris at sunrise/sunset using an astrolabe (or quadrant, octant, sextant)  Longitude by the stars was a lot tougher, and not widely used til the 1700s.Accuracy of charts isn't really important if you're offshore. Charts showed latitude and longitude and approximations of the coastline. More important when operating along the coast were "rutters" -- books of diagrams and sailing directions. The diagrams were sketches showing what a given part of the coastline should look like from your ship when you were safely approaching a port -- how the mountains, trees and other landmarks lined up. The written directions including warnings about hazardous rocks, reefs, shallow sandbars etc. Needless to say, these books were highly prized and considered company secrets by merchantmen.As for practical navigation closer into shore, you're relying on other tools. One of the biggest is a leadline, or depthsounder -- a chunk of lead on a rope thrown over the side then hauled back to determine the depth. Other signs that are particularly valuable at night: changes in the direction and speed of breeze closer to land, changes in cloud cover over land, the smell of the air if the wind is coming from the shore, and the ominous sound of waves crashing on the shore. As for sails, it depends on the weather, the skill level of the crew and your sense of urgency. You can carry the same amount of sails at night as at day as long as you're confident about the crew's ability to strike sails quickly if a squall comes up. For an experienced crew, setting and striking at night or day makes no difference. If you're short-handed, or if the crew is more inexperienced, you're likely to reduce sails overnight as a precaution. Better to lose a couple knots of speed for the night than to lose the rig in blow.If you're operating along the shore though, you are likely to reduce sails and speed in order to make it easier to cast the leadline, and give yourself time to get out of a bad situation.Hope that helps. Carl</blockquote>

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