The tide chart is provided to let paddlers know when they will be travelling with and against the tide. It also lets you estimate your times of arrival at the checkpoints.
Here is an example of how to plot a course on the tide chart, using a Brooklyn or Bust double (BorB2) starting at 4.30pm and finishing 13 hours later as a typical case. You can apply a similar method for whatever craft you may be paddling.
Tide flow on the Hawkesbury varies, but can add or subtract up to 2 kilometres per hour (kph) to your normal paddling speed. So for a Brooklyn or Bust double kayak with an average speed of 111km/13hrs = 8.5km/h, they can hope to travel at 10.5km/h at peak outflow, while they will struggle along at 6.5km/h when the tide flow is most adverse. Such a large variation in speed clearly affects your ease of passage down the river and when your landcrew might expect you to arrive at the major checkpoints.
Plotting your course
Plotting your course on the tide graph will let you estimate your arrival time at the major checkpoints.
You need to know
Start Time: See the Start Time chart in this booklet. For BorB2, its 4.30pm.
Course Time: Estimate of the number of hours to complete the course. Allow for whether you feel you will be faster or slower than paddler norm. For our BorB2 example, its 13 hours.
Estimated finish time: This is the start time plus course time. For the BorB2 crew, its 4.30pm + 13hours = 5.30am.
Plot your base course: You can now plot your base course on the tide graph. Follow these steps:
- Plot start time on left vertical axis, point A.
- Plot finish time on right vertical axis, point B
- Join A to B with a straight line (no-tide course). This would be your time down the river assuming no tidal flow and no stops at checkpoints.
This diagram can be downloaded from here.