Fun and Games in Moreton Bay
01 November 2017 | behind Moreton Island, Queensland
After 700 miles finally we reached the Australian coast. Experienced sailors will say that the most dangerous part of any passage is when you are near land and such was the case as we entered Moreton Bay. The tide had just started ebbing and so the current was against us as well as against the 20 knot North Easterly wind that was behind us, so conditions weren't ideal as we approached the sandbar at the entrance to the North East channel.
....And it was night of course.
This is a small craft channel and I would guess is not dredged and is not surveyed regularly but is charted and marked with beacons.
We pulled down most of the sail and turned on the motor just in case things went pear-shaped crossing the bar. Keeping one eye continuously on the depth sounder, the readings were as expected, dropping down to around 6 metres with some wind verses current conditions on the surface creating some smallish breaking, standing waves. Then we dropped over the bar and into the channel and the depth gradually increased to the charted depth of around 12 metres.
All over bar the shouting .... or so we thought. About a mile (two kilometres) along the channel I was preparing to hoist more sail when the shallow water alarm sounded on the depth sounder which we had set at 5 metres. No it wasn't possible. I raced back the helm and saw the depth still reducing. So my first thought was that we had drifted out of the channel but both chartplotters showed that we were still in the channel (the top green arrow). Frances worked liked a madwoman furling the mainsail while I took the boat off autopilot and tried to work out whether we should go port or starboard to find the deep water. You can see from the screenshots how the peaceable passage down the channel turned suddenly into a nightmare. The depth shoaled to 3.9 metres, less than 2 metres under the keel so we didn't have a lot to play with and didn't know just how shallow it would get. After less than a mile of frantic searching, the water finally got deeper and we again found the channel (the lower green arrow) and were back into 12 metres of water. What a relief but it took some time before the adrenaline levels returned to normal. It was a very unpleasant situation with the potential for disaster - if the tide had been low we would have been lucky not to go aground and, under such conditions, we may have caused some damage to Monkey Fist. But we escaped unscathed. I later reported our finding to the relevant authorities in Brisbane for what it's worth.