DEPARTURE

The SW-NE orientation of the Thames means that strong SW or NE winds can affect tide heights, times and flow.

Wind against tide produces a characteristic short, steep chop which becomes unpleasant above F4. The offshore sandbanks are endlessly shifting and buoys are frequently moved, so even up-todate charts should be used with caution. However, waves breaking on the banks can be seen from some distance, and you can use the tides to your advantage. The flood runs SW into the Thames and the ebb runs NE, so leaving Harwich at half ebb helps you to stay north of the main sands as you make your easting. You then have the full benefit of the flood as you turn south. The feasibility of the outer route via Long Sand Head and down the outside of Kentish Knock will depend on the winds, but it provides fewer waymarks and takes you very close to the Sunk TSS. Taking the inner route, from Pye End (LFL 10s) to South Cork (Q(6)+L. Fl.15s), the Naze Tower day mark watches over you to the west. Out past NE Gunfleet (Q (3) 10s) you can start to feel isolated, but the Gunfleet Sand windfarm to the southwest should orientate you. From Sunk Head Tower (Q.7M Whis) and down the buoyed channel of Black Deep, the London Array wind farm will guide you to Fisherman’s Gat. A bearing of 173° takes you towards East Margate (Fl.r.2.5s) where the chalk cliffs beneath the white tower of the North Foreland lighthouse (FL(5)WR.20S57M19/15M) will emerge. Keep parallel to the cliffs as you head south and aim to meet the Ramsgate channel between starboard hand No3 buoy (Fl(g)2.5s) and southerly cardinal No5 (Q(6)+ Lfl.15s). Leaving Ramsgate for Harwich, pick up the start of the north-going flow about 1 hr before HW Dover and carry the ebb before picking up the flood into the Orwell or Walton Backwaters.