Tide Calculation for Secondary Port Patrick
A vessel of 8.00 m mean draft wanted to pass over a shoal of 8.3 m with 0.5 m safety margin in AM tide on 2nd February 1991 on the approach to port Patrick. What is the earliest time at which she could do that? (ATT 415)
Required depth of water = draft + UKC = 8 + .5 = 8.5 m
But depth of shoal = 8.3 m
So, required height of tide = 0.2 m
Secondary Port: Patrick and Standard Port: Liverpool
Date: 2nd Feb’1991 at AM (After midnight)
From the graph it is confirmed that, the required height of tide will be after 1950 hour on 1st Feb’1991. So, Earliest time on 2nd Feb will be just after midnight that means 00 01 hours.