It's all about the bar! Wide Bay Bar that is. It's the first real test of navigation when headed North from Brisbane. The first two times we crossed was nerve wracking, but we crossed safely and that put that particular demon to rest. Move aside for mother nature and the shifting sands of time and it's all changed again.
The chart below shows the previous recommended track which has been in use for a number of years, with the same GPS way points being given out by the Coast Guard. This month it has been changed. Also, their advice is now to cross at High Tide as opposed to crossing on a rising tide.
So, to give you, the reader, an idea into my thinking and planning to a crossing of a sand bar, here goes.
So, with the advice being to cross at high tide, that gives two times to enter per day as tides are approx every 12 hours apart.
We would prefer to cross it during daylight hours so as to be able to see breaking waves prior to sailing into them. So that narrows it down to 7am to 4:30 pm to allow time to anchor once across the bar and in the Sandy Straights.
The distance from Mooloolaba previous nights stop to the bar is 54 nautical miles. So at 6 knots avg thats 9 hours to get there.
Currently sunrise is 0630 so if we depart then, we arrive at 1530. Which is perfect for a crossing in between 1530 - 1630.
The chart shows Sunday 21st to have a very suitable Tide time.
To cross in daylight without anchoring or waiting to cross, we have a very narrow window of opportunity.
This is all to give us the absolute best chance to cross safely. If the weather is totally benign ie: None or very little wind and swell. None of this matters as the minimum depth now of 3.7 meters which is not a problem to a boat that draws 1.4 metres.
If the swell was 2 meters IE: the sea is rising and falling 2 metres, that could potentially put us very close to touching bottom. Also, a 2 metre swell in deep ocean when it gets to the shallow 3.7 metre sand bar could have waves standing up an breaking.
The chart of wind and swell above is indicating that Sunday 21st in the afternoon is 10 to 15 knots of breeze with a swell of 1.6 meters. So, that all looks on the surface to be a good time to cross the Wide Bay Bar.
Weather is a very precise, imprecise science, so you line up your ducks and take your chances. Seeing as we are currently 2 1/2 days away from the Wide Bay Bar, we need to set off Friday to cross Sunday afternoon.
That is as long as the weather forecast does not change between now and then, which it will because that is what weather does, it changes.
So, it's a matter of keeping your eye on it and being prepared to see the changes and change your plans to fit the weather.
Crossing ones fingers and stroking a dead rabbits foot while twirling around on one leg saying prayers to a divine being of your choice probably will not help, on the other hand, I cannot see it doing any harm either.