There are 63 routes covering most passages across the Estuary. The Routes are primarily, the ‘inside routes’; those that weave through or cross the various sands. But the Second Edition also includes the ‘outside’ route between Ramsgate and Harwich Harbour and the Deben. Please see the ‘Routes’ page for a full list of all the routes covered.
For clarity, each route is broken down into a number of sectors, each generally corresponding to a change in course.
Each route is described in the text of the book, fully illustrated and with guidance on hazards and other detail. Comprehensive waypoints are provided for each route.
This section brings together all the data you require for passage planning and the passage itself into one place. So here you will find:
Route detail of each of the 63 routes - distance, sector numbers and waypoints;
Sector detail - rhumb line data in degrees (T) and distances;
Waypoint detail - by Lat/Long and a brief general description.
Rolling Roads for each route - ready to be open on your chart table for preparation and during the passage.
Passage Planning Tables - For average boat speeds of 4, 5, 6 and 7 Knots: Springs and Neaps
This is the unique feature of the book.
The problem with passage planning for transit across the Thames Estuary is that each route is effectively a number of different sectors requiring a course change, often meeting the tide at a different angle.
For many, passage across the Estuary will be impossible on a single favourable tide so a compromise is required. Where do you take the adverse tide? At what point will an adverse tide have the least negative effect? For some, depth of water over the sands will be crucial; this may mean losing the benefit of some of the tide for later in the passage.
Because of these factors, passage planning will be far more complex than the south coast cross-channel passage. But these planning tables remove the difficulty in selecting a start time for your passage and reviewing the implications of that choice in crossing the shallow banks and arriving at your destination.
The Time Planning Tables enable you to quickly:
Estimate the overall duration of the passage for different start times;
Observe the effect of the tide in each sector for each 15 minutes of the day;
Determine the best start time for the passage (by reference to High Water Sheerness);
Quickly modify your start time to meet any tidal gates while on passage;
For most, many passages cannot be completed in a single tide - choose the compromise to get the best out of the tide;
Determine your likely arrival time at the Landfall Waypoint.
A ‘Planning Assistant’ folds out from the rear cover - OR - download the pdf file from the Downloads page to print off extra sheets to keep on board
How do the Tables Work?
Each Route is divided into a number of Sectors. In the Tables, each Sector has three columns showing a start time every 15 minutes relevant to HW Sheerness, the duration in minutes to complete the sector for the chosen start time and the time relevant to HW Sheerness when you complete the Sector. So know your start time for that sector (relative to HW Sheerness) and you can instantly read the estimated time you will reach the end waypoint. By using that ‘end’ of sector time as the start time of the next sector, you can immediately know the expected time of reaching the end of the next sector. On so on until your journey plan is complete. All the tide calculation is already done for you.
The column of ‘duration’ times for each sector enables you to see at a glance the most favourable tide by scanning the column. Review your plan quickly and easily to take any adverse tide in the best place.
Want to ensure you arrive at a landfall waypoint with enough flood to carry you to your destination at the head of a River? It is as easy to start at the final ‘arrival’ time you want and work back in reverse order to see the start time for the passage.
Want to ensure you reach a crossing point for one of the sands on a rising tide? Identify the crucial sector, select a start time for that sector for the state of tide you want and read the tables, first, backwards to find the departure time and second, then forwards for the estimated time of arrival at the landfall waypoint. Do not forget that the tide will have turned at various points in the Estuary at different times: for example the tide will have started to flood at the Middle Sunk before Low Water at Sheerness. Details of these differences for crucial points in the Estuary are shown in the route guidance information.