Sir D,
You have a low low tide at 10.30am moving to a high high tide, so a bit of water movement.
You get a fair bit of current moving past the islands in a north south direction, less inside, so I would time my run with the tide.
If you sail out under Green and head north on the ebb tide, before looping back to the West between St Helena and Green Island, and use the incoming tide to help push you home?
Look out for the wee lump to the NE just off the Lockyer, head East a bit before heading North.
Edit: I know she's a dinghy, just habit I suppose to point out the shallow parts
Cheers,
SB

I don't think anything over 10 knots will kick in till after 1500 and if you leave at 1300 it will be close haul and head to wind until you turn at top of Green then sprung sheets.
www.bom.gov.au/marine/wind.shtml?unit=p12&location=qld-bris&tz=AEDT

Hi SirD,
Craig's comment is worth noting. We had a chat to the water police yesterday and there is no sign of the two fishermen lost last weekend off Green Island in a similar sized boat to you.
The following is a bit of a passage plan for your route in a pure northerly.You might have to bend it a bit to gauge tacking angles for a NNE, but at least it gives you an idea.
I've used a close hauled angle of 55 degrees to windward, which I guess your boat should be able to manage?

Because of the time you are leaving, use the inside of Green to get North first, there is a little bit less current to fight, then head East on a beam reach to get out between St Helena and Green. I've used a square ddw run to get south,you may want to gybe a few times and run some angles, depends on your boat.
Head west between the Lockyer and the Hybers marks, and it's a beam reach back to Manly.
Hope this helps.

Datawiz said..

shaggybaxter said..
Hi SirD,
Craig's comment is worth noting. We had a chat to the water police yesterday and there is no sign of the two fishermen lost last weekend off Green Island in a similar sized boat to you.
The following is a bit of a passage plan for your route in a pure northerly.You might have to bend it a bit to gauge tacking angles for a NNE, but at least it gives you an idea.
I've used a close hauled angle of 55 degrees to windward, which I guess your boat should be able to manage?

Because of the time you are leaving, use the inside of Green to get North first, there is a little bit less current to fight, then head East on a beam reach to get out between St Helena and Green. I've used a square ddw run to get south,you may want to gybe a few times and run some angles, depends on your boat.
Head west between the Lockyer and the Hybers marks, and it's a beam reach back to Manly.
Hope this helps.

Nice work SB

yes very nice of you Shaggs , well done !!