@hamilton you are correct. The time we are looking for is HW at 1819 so the -12 minute time is correct (since the "Difference table" for Stansore has -10 minutes at 1800). The editor must have been confused when it was mistakenly changed to -28
Thank you for the teaching. May I ask whether we do need to calculate Low Water Tide time 11:21 and 23:50 separately if Low Water Hight is not the same , 1.8 meter at 11:21 and 23:50, at Standard Port of Portsmouth from the Almanac.
