Navigation / sub-sea springs

Thanks a lot John. Would you happen to know about the same discharge phenomenon in the South West of WA? In the case of the WA Tamala limestone discreet discharge can be observed in a few places. Anecdotal stories from fishermen obtaining fresh water from upwellings in the ocean abound around the WA coast, but no firm locations are known. Actually, that's what I am looking for, at the moment. But any information on other places will be great too! Cheers.

Personally never heard of the same in WA but would not doubt that the effect would be found in the south west as the area has huge and extensive limestone areas.
I have cave dived the Nullabour Plains caves and these are quite unique in that they have a relativley stong water flow in most as oposed to the Mt Gambier caves where only the outlets near the coast have disernable flow, all the cave and sink hole systems further inland have such a small flow you can't detect it.
The Nullabour cave water has to go somewhere and I would guess due to the depth that the water table is found in this region that it would surface somewhere far out to sea in the Great Australain Bight.

I would think that the tale you hear about of the fishermen getting fresh water out at sea is just that a tale, the water flow would have to be huge to allow a degree of separation between salt and fresh long enough to fill a bucket.

So interesting. Thanks a lot. As for filling bucket of fresh water offshore, it is possible. As an example, an old gentleman from Nannup used to do it when shipping offshore Capel in the 1930s. I'd be happy to find the source. It's no longer bubbling on the surface, but it's still there. Another famous one is located offshore Albany. Otherwise. it's still kind of current practise in the Mediterranean sea, Phoenicians' way! I have nice pics. But over there, it is in a karstic environment; sub-sea springs are many and relatively easy to localize.
I will investigate about Nullabour cave and let you know. Thanks again.

Re. Oondiri. It is indeed one of the largest karstic formation in the world. I wonder if the variation in land height is enough to have underground discharge at sea.

In the case of the Mt Gambier caves, couldn't it rather be a sort of Ghyben-Herzberg Lens phenomenon (with fresh ground water sitting directly on an intruded body of salt water)?

(You are not involved in WestWater, are you?)

Don't know for sure about the fresh on salt theory for Mt Gambier.
But I some how think it is not the case, based on all the years of my involvement in the area nobody ever offered that as an explanation.

I think Mt Gambier limestone acts a a pure aquifer with the water entering the formation many km's north of the Mount and discharging at the coastal and offshore areas several million years later.

Sub salt levels has never been raised as an issue in this area to my knowledge.

Sorry nothing to do with Westwater.

Discharge takes place close to shore by seepage on the west coast of WA. It's probably an explanantion. That's anyway a good encouragement to investigate this zone further! Thanks!