Passage planning for Busselton
With plans to head north for winter, we were keen to get some miles under our belts. Having finished our work at Rotto, we decided that March in Geographe Bay would be the perfect primer.
Time to pull out the chart and refresh our route planning skills….
Rottnest Island to Busselton is a comfortable passage that can be broken into three segments:
Rottnest Island to Mandurah - 25 nautical miles (nm)
Mandurah to Bunbury - 50 nm
Bunbury to Busselton - 25 nm
Whilst we rely so much on our electronic devices and software these days, you can’t beat pulling out a paper chart and being able to view a passage in its entirety. It also allows you to carefully study the route to identify the reef and other hazards along the way.
The first route to Mandurah has a few areas to negotiate, including Five Fathom Bank - a lot of craypots and fisherfolk; Coventry Reef - which has a bommie that breaks in small swell and James Service reef - which runs between Warnbro and Mandurah.
Planning to leave Rottnest pre-dawn in order to maximise the easterly winds, we were going to be in the dark initially and thus decided we would sail west of the three groups of reef. As our first sail through this area, we were also looking for the least risk, but this meant that our westward route would be a little farther to travel and more exposed to the easterly and therefore rougher.
First action was to identify a couple of hazards and highlight these on the paper chart; then subsequently plot them on our electronic plotter. This identification ensures that we know where we shouldn’t be!
Then it is a simple matter of plotting a course in safe water and identifying waypoints along the way. Waypoints are simply guide posts along the way so you can ascertain your position at a certain point in time and therefore determine time to arrival at your end point. Your arrival time must be considered against a forecasted weather change, sunset, a desired tide state or fuel useage. Of course all this is done for you on the chart plotter, however what happens if that chart potter has a hissy fit? An hourly position fix onto the paper chart provides the reassurance and insurance should you lose your electronics.
The great thing about our modern phones and tablets is that we can also run our navigation and other systems on them and this provides us with additional redundancy.
Of course plotting a course does not necessarily mean that you will stick to it. Leaving Mandurah we found the wind to be coming from the south more than predicted and as a result couldn’t hold the right wind angle to allow us to passage inside Bouvard Reef. Having already identified a couple of key shallow areas, we were able to set a new course passing westward of them; this course putting us offshore from Bunbury. The plan was to then take advantage of the afternoon southerly and tack back into our destination, but of course the forecasted southerly never came - it blew dead easterly all day at Bunbury - so we motored in the last 8 or so miles.
One thing we like to do at the end of each sail is to debrief and talk about what was good, what was not so good and what we were glad no-one else was there to witness! This honest feedback to each other keeps it real and also helps us to improve our skill levels. It is good to then research and read up on an area where we didn’t do so well and then polish it for next time.
All part of this big learning journey we are on.
You can’t beat a paper chart to give you a greater sense of the passage you are undertaking.