Paul BrownTides – Chartwork 3 rd Class Chartwork 3 rd Class Tides (Adapted from RYA Shorebased slides)

Paul BrownTides – Chartwork 3 rd Class What Causes Tides? Gravitational effects of the moon (and sun) which exert a pull on the water on the Earth's surface. What terms have you heard relating to tides? High Slack Ebb Flood Neap Range Stand Low Spring

Paul BrownTides – Chartwork 3 rd Class TIDES Sun Earth Moon

Paul BrownTides – Chartwork 3 rd Class TIDES - SPRINGS Earth New Moon Sun

Paul BrownTides – Chartwork 3 rd Class TIDES - SPRINGS Earth Full Moon Sun

Paul BrownTides – Chartwork 3 rd Class TIDES - NEAPS Earth First Quarter Neaps Sun

Paul BrownTides – Chartwork 3 rd Class TIDES - NEAPS Sun Earth Last Quarter Neaps

Paul BrownTides – Chartwork 3 rd Class TIDE TABLE 18 TH m m m HW LW Range 4.1 metres GMT

Paul BrownTides – Chartwork 3 rd Class TIDE TABLE 18 TH m m m Add an hour for British Summer Time

Paul BrownTides – Chartwork 3 rd Class TIDAL HEIGHTS - DEFINITIONS Chart Datum Charted depth (sounding) MHWS MLWS MLWN MHWN Depth of water Charted height Drying height

Paul BrownTides – Chartwork 3 rd Class TIDAL DIAMONDS & DATUMS Tidal streams referred to HW at PLYMOUTH

Paul BrownTides – Chartwork 3 rd Class TIDAL DIAMONDS & DATUMS 3 hours before HW Stream setting towards 318(T) Springs 2.9 kn Neaps 1.5 kn

Paul BrownTides – Chartwork 3 rd Class TIDAL STREAM ATLAS Atlas gives Direction & Rate of tidal stream for each hour 4 hours after HW PORTSMOUTH

Paul BrownTides – Chartwork 3 rd Class TIDAL STREAM ATLAS Thick and long arrows show strong stream Short and thin arrows show weak stream 4 hours after HW PORTSMOUTH

Paul BrownTides – Chartwork 3 rd Class TIDAL STREAM ATLAS 03,05 Rate of stream 0.3 kn at Neaps 0.5 kn at Springs 12,23 Rate of stream 1.2 kn at Neaps 2.3 kn at Springs Stream Slack