HARWICH CHANNELS (including the Harwich Deep Water, North and South Channels) Masters of vessels should navigate with extreme caution in the Harwich Channels and their approaches, as deep-draught ships and crossing traffic may be encountered. REGULATORY SYSTEM - Vessels must use the North (inwards) and South (outwards) Channels unless confined by their draught to Harwich Deep Water Channel or unless otherwise expressly permitted by the Harbour Master.