ASA 105: Skill 8, Tide and Current
8. Use the tide and current tables to find: Times and heights of tides at reference and secondary ports. Direction and rate of current at referenced and secondary stations. Tide is the vertical movement of water. Current is the horizontal movement of water. The two are related. On the US East Coast the tidal cycle is diurnal with high tides occurring about every 12 1/2 to13 hours. Refer to Eldridge 2022 Newport pages and note that high or low tides are a little later every day. The tidal range varies as well. Time of high or low water and tidal range are not the same everywhere. Refer to the Boston pages, for example, to see that the time of high water is three hours later than at Newport and the range is 9.5 ft. Boston and Newport are among the list of primary tidal stations. Secondary stations are noted separately on pages 12 through 20. Page 15 shows the time of high water at secondary stations located on chart 1210 ...