DOKUZ EYLUL UNIVERSITY SCHOOL OF MARITIME BUSINESS AND MANAGEMENT DEPARTMENT OF DECK E.Gürel TIDE CALCULATION ADMIRALTY TIDE TABLES

E.Gürel

E.Gürel Admiralty Tide Table (ATT) are published in four volumes; 1.United Kingdom and Ireland (Including English Channel Ports). 2.Europe (Excluding United Kingdom and Ireland), Mediterranean Sea and Atlantic Ocean. 3.Indian Ocean and South China Sea (Including Tidal Stream Tables). 4.Pacific Ocean (Including Tidal Stream Tables).

DOKUZ EYLUL UNIVERSITY SCHOOL OF MARITIME BUSINESS AND MANAGEMENT DEPARTMENT OF DECK E.Gürel

E.Gürel CHART DATUM PREDICTED LW WATER LEVEL PREDICTED HW CHARTED DEPTH SOUNDING ( DOW) HEIGHT OF TIDE ( H.O.T ) RISE OF TIDE ( ∆H ) RANGE LW HEIGHT HW HEIGHT

DOKUZ EYLUL UNIVERSITY SCHOOL OF MARITIME BUSINESS AND MANAGEMENT DEPARTMENT OF DECK E.Gürel Charted Depth: The depth on a chart is measured from a level known as Chart Datum (CD). On a modern chart, Chart Datum is normally placed at the level of the Lowest Astronomical Tide (LAT) which is the lowest level which can be predicted to occur under average meteorological conditions and under any combination of astronomical conditions. LW and HW Heights: LW and HW heights are always measured from Chart Datum. Rise of Tide (∆H): Rise of Tide is the vertical distance measured from LW to the actual water level. Height of Tide (H.O.T): Height of Tide is the vertical distance measured from Chart Datum to the actual water level.

E.Gürel Find the actual sea level, if the C.D is 14,3 m. at 06:20 (GMT) on 1 st February Duration: HWT – LWT 10:44 – 03:19 = 7 h :25 m (Falling) 2. Range: H of HW – H of LW 6,1 – 1,7 = 4,4 m. 3. Δt: HWT – DT or DT – HWT 06:20 – 03:19 = 03 h :01 m

DOKUZ EYLUL UNIVERSITY SCHOOL OF MARITIME BUSINESS AND MANAGEMENT DEPARTMENT OF DECK E.Gürel C.D 14,3 SEA BOTTOM LW 10:44 H of LW: 1,7 HW 03:19 Range:4,4 06:20 W L HOT ΔHΔH H of HW: 6,1 DOW = 14,3 + HOT ( ΔH + H of LW )

DOKUZ EYLUL UNIVERSITY SCHOOL OF MARITIME BUSINESS AND MANAGEMENT DEPARTMENT OF DECK E.Gürel There are two different ways to find the ΔH.

E.Gürel First way is to find ΔH = Range x Factor Actual range = 4,4 Δt = 3 h :01 m After HW Sp6,00,63 Np3,20,59 2,80,04 1,2 F F = 0,02 Factor= 0,59 + 0,02 = 0,61 Δh= 4,4 x 0,61 = 2,7 m. DOW = 14,3 + 2,7 + 1,7 = 18,7 m.

E.Gürel Second way is to find ΔH with Curves Δt = 3 h :01 m After HW HW = 6,1 m. LW = 1,7 m. HOT = 4,4 m. DOW = 14,3 + 4,4 = 18,7 m. Actual range = 4,4

DOKUZ EYLUL UNIVERSITY SCHOOL OF MARITIME BUSINESS AND MANAGEMENT DEPARTMENT OF DECK E.Gürel 1 st February 2000; The sounding taken 17,4 m. by echo-sounder at the noon. If the C.D is 12,7 m. Find the exact time. 1.Duration: HWT – LWT 15:43 – 10:44 =4 h :59 m (Raising) 2. Range: H of HW – H of LW 5,7 – 1,7 = 4,0 m. 3. Δt: HWT – DT or DT – HWT ?????????????????????????????

DOKUZ EYLUL UNIVERSITY SCHOOL OF MARITIME BUSINESS AND MANAGEMENT DEPARTMENT OF DECK E.Gürel C.D 12,7 SEA BOTTOM H of LW: 1,7 HW 15:43 Range:4 At noon W L HOT ΔHΔH H of HW: 5,7 17,4 = 12,7 + ΔH + 1,7 ; ΔH = 3 m. LW 10:44 (DOW) Sounding 17,4

DOKUZ EYLUL UNIVERSITY SCHOOL OF MARITIME BUSINESS AND MANAGEMENT DEPARTMENT OF DECK E.Gürel There are two different ways to find the Δt.

E.Gürel First way ΔH = Range x Factor Actual range = 4 3 = 4 x F F = 0,75 Sp 6,0 1 h :42 m Np 3,2 2 h :02 m 2,8 20 m 0,8 f f = 06 m 2 h :02 m – 06 m = 1 h :56 m 1 h :56 m Before HW 15 h :43 m 1 h :56 m 13 h :47 m

E.Gürel Second way is to find Δt with Curves Actual range = 4 HOT = 4,7 HW = 5,7 m LW = 1,7 m HOT = 4,7m Δt= 1 h :56 m 1 h :56 m Before HW 15 h :43 m 1 h :56 m 13 h :47 m

DOKUZ EYLUL UNIVERSITY SCHOOL OF MARITIME BUSINESS AND MANAGEMENT DEPARTMENT OF DECK E.Gürel THIS PRESANTATION WAS PREPARED BY EVREN GÜREL E MAIL : : Mobile Phone: Phone :