Blue Lake Mt Gambier, South Australia, Australia
By setsujoku on 11-Jun-12. Waypoint GC3NBNG

Nice place to walk

Finally, 12 years after this was published, and numerous time in The Mount, I've stopped to see the sights and get some answers in the geoscience lesson!Answers emailed to CO.TFTEC

Luckily we were here when the lake indeed was blue! According to google, it turns blue because of micro crystals of calcium carbonate. Thanks for the EC at this amazing location!

Beautiful spot

We are spending a few days in Mt Gambier and visited the Blue Lake today. I have sent my answers to the CO and hope they pass muster. My grandmother used to use some blue stuff when washing sheets and towels. It was a hard pellet and came in red and white striped paper, and you could also put it on bee stings. It was the same colour as the lake. I think someone threw some of this blue stuff into the lake. That's my theory.

Very chilly here this morning but sensational colour!

Thanks! Great view

Blue Lake was visited today as part of our Introductory Geocaching Day long weekend in Portland. We have been here quite a few times in the past 40 years and always enjoy our visits.It was a fantastic day today as +Wife and I drove a loop from Portland through Nelson, here and out to Puralka before heading back to Portland for the night. Thanks for the Earthcache. *Answers sent for both of us.*

Was a lovely but windy day today for earth cache day

Thanks for the earth cache, the sun was stuck behind some clouds today. And the rain was starting to come down so we made a dash for cover in the car. Happylife72 accompanied me today and together we found the answers.

P Did your Blue Lake today. 1 October 2024 5:56 pm Tyfc setsujoku total caches now 6945 .

Found on my lunch break. Been past many times but only just decided to get this ticked off. Ill say the microorganisms in the water change the colour as the temperature varies through the year

What an amazing place! It was insanely hot when we visited, but the beauty of this spot blew me away! Thank you for taking the time and trouble to create this earthcache.I would like to show my respect and acknowledge the Traditional Custodians of the Land, and their continuing connection to it. I wish to pay my respects to Aboriginal and Torres Strait Islander cultures; and to Elders past, present and emerging.

On the way to explore Port McDonnell today. Have to admire the sunny weather I def got lucky this weekend for my mini vacay at Mount Gambier. The Blue Lake was wintery grey today, but still an amazing sight. Chatted to a couple from Melbourne here. Told them about my marathon drive from coast to coast and back. Must remember to check the trip meter tomoz when I get back to my starting point. Ive been fairly selective about which earthcaches to log, as therere so many around this region. The Blue Lake was a must TFTC setsujoku

TFTC,Time to head home after a massive trip through NSW, Qld., NT, WA, SA and still to come Vic. Visited trackables and added a favourite.Great EarthCache,

Setup camp at the nearby Caravan Park, came for a walk. 1st was the earthcache, got all the information needed, snap taken. Thanks to CO

Travelling with iluvtrekking from our home state of WA on. SA caching foray. Staying in Mount Gambier for a week to grab some of the local hides. Its been sixteen years since since we were last here so enjoying the re-visit. Love the country town caching. Thanks for the EC - Answers sentLNCU

We are travelling with richlink on our Annual Caravan Geocaching road trip, using geocaching as our guide. We are in Beautiful Mt Gambier for a few days, soaking up the amazing things this area has to offer. We especially love the bush, the back roads, and the wild southern seas. TFT Earth Cache. LNCU.

Our first glimpse of the lake and although not particularly blue was still an impressive sight. Thanks for placing this cache here and making it an earthcache. My fave. Tftc

#14,622. Blue Lake was one of the highlights of our recent visit to South Australia (over here with Infoferret). Its such a wonderful colour in late summer. Hard to credit that colour can change so quickly at the end of spring and with the cooling temperatures of autumn. It certainly wasn't cool on the day we visited. Stinking hot actually. But really loved taking photos of this jewel of the Gambier. Anyhow have emailed the CO with my answers which I found on display boards and online to explain the colour change phenomenon. Thanks so much for highlighting this feature with your earthcache.

#19733 - 1:32:00 PM; Day eleven of a road trip taking the long way to Adelaide from the National Capital and back again with the geohoney. After spending the night in Robe, we are headed east for Port Campbell. Stopped off to visit the Blue Lake as we passed through Mount Gambier and gathered the information required for this earthcache while we were there. Answers sent to the CO to get the OK. TFTC setsujoku

Visiting Mt Gambier and staying at the coastal town of Robe. I remember looking over this very lookout to the beautiful blue lake 6 years ago. What a wonderful place! TFTC! #118

We think temperature causes change in the colour. Tftc

The Blue lake was thankfully still blue when we visited on this gorgeous Easter Sunday! We weren't sure if we had missed the blue hue and would be greeted with grey but were pleasantly surprised at just how blue the lake was. I like the theory that the Calcium Carbonate forms crystals that cause more blue light to be reflected on the surface as the weather warms. It was definitely a warm day when we went which was perfect for picnicking on the hill overlooking the water.Thanks for a great cache!

Incredible!

Travelling around the area so had toCome and see the blue lake and thankfully it was blue at the moment. A spectacular sight. There were lots of people walking around the rim which was great to see. Why does the lake turn from blue to grey? Maybe the amount of water and minerals filling it at different times of the year. Thanks for the earthcache. It was a beauty. A fantastic feature of Mt Gambier.

WOW, It is obvious as to why the water turns grey in winter. Winter is known for its dull, cold and gloomy presence, so called grey time. During summer the sun is shinning brightly and everyone is happy. The birds are chirping, the trees are blossoming, the locals are out enjoying the nice warm days, the kids are playing in the parks and even flying kites. Then comes along the grizzly, dark time of winter, the cold dark expectations of the misery ahead. The cold, the icy conditions and the grumpy attitudes of the locals just effects everyone. So much so it affects the sun and she cries. She cries so much during winter that the rain discolours the water and will only turn blue again when the nastiness of winter has gone and the sun can share it's fun to all around again. These facts were taken from the Mickipedia book of knowledge. So I have thoroughly enjoyed my caching in South Australia. The weather has been great, the people have been great, the food has been great, the countryside has been great, the wines were great and the caches were great. You could say I had a great time. Just a few caches today before I board a plane and head back to the heat and humidity. Cars dropped off and bags packed, lucky I still have a cacher with an extra late flight. We drove around Adelaide collecting target caches before being dropped off at the airport. The caches were signed and replaced as found, a great way to finish off a great weekend, actually it was a week. There is so much more to still get, until I return.

Next day of our roadtrip. Today we're driving about 350km from Meningie to Mount Gambier. The first stretch is quite long and lonely along Coorong NP. Then we pass Kingston, Robe, Millicent and arrive finally at Mount Gambier. Great views everywhere and of course we pick up a few caches along the way. We were lucky, the lake is still vividly blue. Beautiful! Like Crater Lake in Oregon. As to the colour change - maybe this is due to some algae that are there in summer and not in winter? Thanks and kind regards from Switzerland, Hinni&Simo

Took a trip around Mount Gambier's geological highlights this evening and have sent answers with our theory. TftcPic of Mr BLB at the Blue Lake

Wow!! Just wow! What a beautiful landmark to have in your city! This stunning lake/crater was one of the major reasons for our visit to Mt Gambier and certainly did not disappoint. We walked the whole loop while park run was on, just stepping to the side when they were passing. Hadnt known that the hydro station was here, nor that it is the towns water supply, so that was new. Never get sick of this view!

We were in Adelaide for The Great Leap Forward (Mega-Event). After the event we made our way through to Mt Gambier, and cached a few random caches in the surrounding areas.I found your cache, Blue Lake today. This is my 2945 find.Having a girlie trip with Duppers and At The Lake House. Signed as Saddle club to save room in the logbook.setsujoku, TFTC, TFTH & TFTSF

AtTheLakeHouse, Shazzar66 and I spent a busy but successful day and a half in Adelaide for the Great Leap Forward, Leap Day Event. The next morning we headed towards Mt Gambier, stopping at many more caches that were on our list, making the journey a lot longer than a straight drive. Our list included Oldies, good or needed D/Ts, caches with high Favorite Points, particular Attributes, Challenge Cachesso many caches, so little time!We were very disappointed to learn that an Old cache, published in September 2004 had been not only Archived, but Locked, because a finder had said that the container was damaged. We didnt know that at the time, so we went to GZ and found the cache, which is still there. Such a shame for caching legacy. We also needed to stop to do an Earthcache near a particular winery, and then we needed to stop for a wine tasting. Ah, the things you do in the name of caching!The next morning in Mt Gambier, after stopping for a mandatory coffee, we visited Blue Lake which was one of the many places and caches that we wanted to visit, of course. Stunningly blue and clear. What a special place. Shazzar66 did parkrun, while ATLH and I were happy just to walk at our own pace and enjoy the view. Afterwards, we continued caching, ATLH got to snorkel at Kilsby Sinkhole, and then we visited the Millicent area for a couple more good D/T caches and some Challenge caches.Next morning, we headed off through Ballarat to Melbourne, again finding caches on the way. Ballarat saw some adventurous caches, again in our well-curated list, and then we were at the airport to head home.Answers sent by AtTheLakeHouse on behalf of our team.

Second time we visit this place. We guess when the water cools in winter causes the colour changes. Greetings from Norway, TFTC:)

BOLD7 having a fab time in Adelaide and surrounds. Lots of laughs and some brilliant inventive caches.!thanks to all the COs on a road trip with chamad and JACS today. Answers submitted by JACS for us. Blue is lots of folks favourite colour so my absurd reason is that Mt Gambier is full of blue colour people who secretly drop dye in to keep it that way!

An easy EC? My fav. Thanks for the info on Blue Lake I had some deep thoughtful reasons why Blue Lake changes colour, but for the life of me, I can't remember. This is just a tribute...

How very exciting the big trip has finally arrived! Down from Brisbane with a host of other geo friends with plans aplenty, enough to almost see us needing to extend or make a return visit. Today chamad, Gcoven and I made a drive for the LGAs heading all the way down to Mount Gambier, picking up interesting caches along the way - this was one of them. Thank you for your cache which has added to my wonderful caching holiday. Photo added and answers sent. As for the crazy idea on the colour change - its a well known fact that once a year the local toilet cleaner factory that makes Blue Loo tips there end of year surplus into the lake and as the rainfall increases over the year it dilutes the colour making it appear more grey which remains until the next annual dump.

WAG: the blue colour is caused by light scattering (like the blue of the sky). When the water cools in winter it becomes denser which causes the scattering colour to change.I don't actually believe this as the colour change happens too quickly, but it's the best I could come up with.

Find # 11443Well here it is, time for another MEGA, and an extra special one to. Its a leap year! So before the main event I decided Id head down to Millicent and surrounds to collect some geoart, and some of the all important (to me) SFE challenges Day 4 and with all the above achieved, time to move on from Millicent. Headed south to Mt Gambier then back up north, caching for counties, oldies, Jasmer gaps, and anything else my travels took me to along the way.Such a beautiful spot here with phenomenal views to enjoy of the magnificent lake. Not at all what I expected.Thanks setsujoku for Blue Lake

Answers have been sent.Doing a road trip

**Today:**Found with DSDMy first ever day in South Australia ??Woke up in Mount Gambier today with no real destination, but a big list of caches! Ended up just up the road in Millicent, but still several hundred kilometres travelled as we detoured down to the coast! The biggest goal of today, and the entire trip, was finishing my AUSMER! We found not only one, but two caches in my final month I needed! Its been a multi-year challenging journey, so good for it to be finished! ---**This Cache:**Yet another superb location in Mount Gambier! Cool to find out this lake is one of a kind, and it certainly was Blue today on this summers day! Its a pity the lookout location is a little bit obstructed by the trees, but we found other spots around the lake on our walk that had better views for a pic! The answers were all found & sent off to the CO. Pic attached Many thanks!

Loci612 will send answers for myself. An interesting location. Thanks for the cache.

Answer sent to CO.I visited the blue lake on many occasions, and Im happy to be able to log this Earth Cache today as my 6000th find. The lake was beautiful and blue today and my father always thought it was the reflection from the sky that made it blue in summer and grey in winter. Now for our road trip to the Adelaide Great Leap Forward Mega to continue

Bullertrout, Nanzie and i are caching our way to Adelaide for the mega. Wow that blue is stunning. Answers sent to CO for all 3 of us. Thanks for the earthcache setsujoku#15200

Found with SPNBT Team Nice easy find paddle chick has sent the answers in this deserves a favorite. Thanks setsujoku

Well after a whirl wind tour of Tasmania to help with 3 challenges that Im working on, I got back in last night packed the car and headed off to SA this morning to attend the Leap Year Mega and to also tick off some LGAs along the way as well.Heading towards Millicent today as I missed the Mega due to the Rona that was going around so it was about time I made a visit there.I finally crossed the border and then gained my 1/2 hour and now its LGA time.I dont know how long its been since I have been to Mt Gambier and it seems such a very bustling town.Did a couple of laps of the lake in the Geowagon and then parked at the required coords.The lake is a brilliant blue at the moment and looks fantastic.Answers have been sent to the CO.Thanks setsujoku TFTEC.

Enjoyed this earthcache. Found with Paddle Chick and Nanzie. Paddle Chick will send you the answers. Always wanted to come to Mount Gambier

Nice cache to do on such a nice day and walk around the lake.TFTC

This was a great place to visit during the summer, and the water color looked spectacular. We had an amazing time exploring and enjoyed learning more about the volcanic landscape in the area. Answers sent to CO by *Filser1* on behalf of both of us.T4TEarthcache

TEMBO! and I visited the "Blue Lake". The colour is unbelievable blue.We transmitted the answers to the owner.The Change of colour is about the warming of the water and the microorganism who react with this change. No other spuky Things.This unbelievable Lake must have a favorite point From me.Thanks to setsujoku for hiding and maintaining the cache.T4TC Filser1

Found with whytknight while in mount gambier

This is truly one of the most amazing places getting around d and a must visit if in the area. Found with Nanaton34TFTC

A quick stop at the Blue Lake before getting dropped and then putting my thumb out towards Warrnambool. Answers sent to the CO. 13 for 15 today on finds and five new LGAs completed.

Discovered the blue lake through a bike ride in the AM and learned about its geology along the way. Amazing location. Answers sent to CO. tftc

The Blue Lake is absolutely stunning! Loved learning about it as well.We think the colour change has something to do with the angle of the sun or the mineral content being affected by the temperature. And now I will be heading off to look up the theories!

TFTC. Beautiful lake

TFTC! 28 December 2023 6:41:24pm 7041Answers sent through the CO! Really love the views and walk up here.We think that the colour changes because of the position of the sun and the sun light hitting the water! Its really stunning here!

Beautiful

The lake was looking beautiful today, extra blue. Came into SA from a holiday in Nelson Vic to go grocery shopping. My first ever cache in SA!

I have had such a great day following around Mt. Gambier. I AM GUR THE SKITZ CACHER

Just amazingCheck!

What an amazing view and vibrant coloured lake! Found during an enjoyable visit to Mount Gambier.TFTC. Answers sent.

We learned a lot ! We came here 15 years ago and are happy to be back!

Super toller Platz!

Last day of our trip to Beachport, Cup weekend 2023, all packed up and on our way home. Took the opportunity to grab a few caches along the way Nice easy earth cache and a great walk around the lake tftc

Heading west today with Selva Girls and grabbed a few caches along the way and this was one of them. Once at GZ the information was soon gathered and answers sent to CO.The changing colour may be the heating of the surface layers and algae and calcium bicarbonate. In winter the surface layers wouldn't heat as much resulting in a greyer colour.Thanks for placing and maintaining this cache for me and others to enjoy.An interersting EC and I've given it a FP from me. TFTEC setsujoku

Konie and I are heading south and west on an adventure. Next, we came to this cache. We gathered the required answers and these have been sent to the CO by my caching buddy on behalf of us both. Lots of photo opportunities here. The changing colour may be the heating of the surface layers and algae and calcium bicarbonate. In winter the surface layers wouldn't heat as much resulting in a greyer colour.Thanks for bringing us here and TFTC

The weather was windy and cold today for a walk around the perimeter. I eventually warmed up and thought about the colour of the water.
(I loved a description I read of the blue loo tablets being thrown in one day a year. )

But, I’m thinking it’s the temperature changes of the seasons as it warms up in summer it turns bluer. Colder weather it is greyer. TFTC
Answers sent.

A lovely lake indeed. We were surprised when visiting the Krispy Kreme store on the highway that they have a Mt Gambier exclusive donut only sold here called The Blue Lake (see in attached pic).

It is obvious then that these do not actually taste very nice and people who have bought them and taken them to the lake to picnic have thrown them into the lake in disgust.
As there are a lot more tourists in summer, there are lot more of these blue donuts floating on the lake giving it a more blue appearance.

TFTC and greetings from Tassie

Stayed overnight at Mt Gambier from Adelaide to see my family and on way back to Melbourne. Nice and cold morning to look around this beautiful lake. Sent answers to CO. Thanks setsujoku for bringing me here and the earthcache

Lovely spot, we reckon it changes colour because during summer time calcium carbonate forms crystal which scatters blue light

Tassie expat and I did the nice walk around the perimeter when we arrived and read all of the information boards. Please refer to Tassies answers submitted to CO.
Thanks very much for the earth cache.

Answers sent to CO for frmen1 and myself.
I think that the water turns blue due to the pH testing by SA Water lol
We enjoyed the walk around the crater rim and it seems to be a popular exercise route for locals. The lake was mainly grey with a tinge of blue, but some amazing blue colouring could be seen in places near the shorelines.
Fav pt given TFTEC

I spotted this one on a road trip from Adelaide which my son arranged for us. Answers sent to CO. I think the change in colour is due to sunlight highlighting (or not highlighting) the minerals in the water.------TFTEC

Great to be back here after a road trip of note. The lake was bluer than last time we were here.

Theories include mysterious elf’s and tinker bell dust to magical crystals. But like the pink lakes, Mt Gambia has its own blue version in summer. Just blue. In winter it gets sad and turns grey…. ️ (Answers emailed to CO).

Mein erster Urlaub in Australien! Wir haben einen Campervan gemietet und fahren von Adelaide nach Cairns an der Küste entlang. Hier an dem dem schönen Blue Lake haben wir unsere Frühstückspause gemacht. Ein wunderschöner Vulkansee, vielen Dank fürs herführen.

TFTC Uhu_Donnervogel

Watawieh from Norfolk Island South Pacific.

After attending the Rutherglen mega I am travelling towards Adelaide with TeamAstro Today’s geo-adventures were from Millicent, through Mount Gambier and Port MacDonnell to Kingston SE.

We had perfect lighting as we drove around Blue Lake. It was certainly Blue this morning. Answers have been sent to the CO. TFTEC

Found & logged using Cachly for iOS

On the way to Halls Gap we made a stop in Mount Gambier to see the Blue Lake. And there was in fact little blue spots to see.
My theory is that the combination of temperatures and sunlight will lead to special chemical processes that blue chrystals will arise. TFTC

Have always wanted to stop by Mt Gambier and finally got the chance after doing the Great South West Walk.
This lake is stunning, I'm sure it is even better in Summer when it is brighter blue.

I'd say it's to do with the minerals in the water when it gets warmer, since we could see it was a nice bright blue around the edges. Tftc

30,547. Found with minniek, albida33, Sol de lune, smittengranny (signing either as FAMSS or MAFSS to save room and just for fun). After the hordes around Rutherglen it was good to drop down to a group of 5.

Rutherglen Mega and South Australia Trip Day 7. Today we had a full day to explore around the Mt Gambier region, with a few older caches targeted plus many others on our list. We started heading along the south coast which was spectacular to see, then back to Mt Gambier. The main event for MG here - absolutely stunning. Info gathered and sent to the CO.

Thanks setsujoku !! Fav Point.

Day 7 of our loop through Vic and SA then home.

Today was our first day caching with albida, Sol de lune & smittengranny. We signed as MAFSS to save room. Some of us may have rebelled and signed FAMSS instead. It was a bit dreary and windy but we didn’t get too wet.

The aim was to collect a couple of counties, old caches to finish my Ausmer calendar, and just to have fun.

All caches were found quickly and easily unless otherwise mentioned.

It has been a long while since I've visited the magnificent Blue Lake. It sure was a beautiful blue today. Nice to see the show. Logging with permission.

Southern Autumn adventure Day 8. Post Mega South East SA trip Day 2. After a driving day yesterday to wrap up the mega weekend, today was a trip from Mount Gambier down to the southern coast line with Sol de Lune, Smitten Granny, Fitzy_1965, MinnieK and me (albida33). F.A.M.S.S was the initial in the logs today. Our goal in this region was to visit the two old caches out this way and a few others that are nearly as old. We also managed about ten Earth caches and even went for a walk or two. We ended the day with caching and LABs around Mount Gambier before retiring for a home cooked meal at the caravan park.

This lake being the iconic spot for Mount Gambier was a must visit. I have not been here for over twenty years, but I do not remember it being as blue as it was today before, even on an overcast day. We worked out some answers and these were sent off for our team.

Thanks for the cache setsujoku

40904.26 TNLN
Visited: World Traveling Gold GC A#6 & June 2022 Tis but a Scratch #2 A#490

**Albida**

Headed to Mount Gambier after the Rutherglen Mega with fitzy_1965, Albida33, Minniek, and Smittengranny. We signed all logs as FAMSS.

We targeted a few older caches, a few multi's, a few puzzles always as well as a couple of earthcaches.......and really anything else we had time for.

A great area Mount Gambier...and the blue lake was looking like it today. Enjoyed the earthcache and our answers have been sent off.

Thanks setsujoku...a neat earthcache about neat spot. Fav point added.

Visiting Mount Gambier on our family holiday. First stop, the Blue Lake!

Thanks for the info! Answers have been sent to CO, photo of some of our family attached!

TFTC!

Answers have been sent by minniek for our group.

Today there were two cars of geobuddies travelling around this area collecting a variety of caches based on age, type and favourites. It was an incredibly successful day and thanks must go to all COs for placing such interesting and sometimes challenging caches. This was one of the caches we found and all were signed either as MAFSS or FAMSS , as the group consisted of minniek, Albida33 Fitzy_1965, Sol de Lune and myself Smittengranny.

The Blue Lake was distinctly blue today, despite it being overcast. Interestingly, Leg of Mutton Lake ISN’T blue. Like the description says, the Blue Lake is the ONLY lake IN THE WORLD that does this. Why is way beyond my comprehension, but I bow to Beaker’s local knowledge of the Master of the Blueness. Thanks setsujoku for showing us how the lake was formed. Answers sent

This cache was found today and brings our overall cache find tally to 12385.

An early start today at Mt Gambier and up here just after the sunrise. I’d love to see this lake in summer. Our answers have been sent via the message centre.

Thanks setsujoku for the cache.

We are staying in Mt Gambier while we explore the Limestone Coast. What a change in the weather, it was so hot a couple of days ago and now it's really cold this morning as we visit the lakes.
We were taken to Valley Lake first. It was pretty. It was a good idea to stop there first because being as its lateish March here at the Blue Lake unfortunately it isn't so blue as the photos my geofriends who were here 7 weeks ago sent to me. In comparison to Valley Lake which was decidely green, Blue Lake is much bluer.

Some spots on one side have patches of vibrant blue. This makes me think that as the earth is in its orbit rotating round the sun and the level of the sun is now lower the angle of refraction of the sun's rays is not sufficient to penetrate the surface water and make the colour appear bright blue, which we could still see in spots at the shallower edges.
But who knows?!?

TFTC # 5292

Catching up on a few logs from last month. Was visiting Mount Gambier for a conference and obviously made time for some caching. Had to come to the beautiful Blue Lake precinct with everything here that is to be seen. Just beautiful! Of course, we found and sent the answers to the questions to the CO. Then sat back and enjoyed this amazing view with this amazing blue lake. Every time I see it it is a different colour. Thanks for the EC setsujoku.

I visited this earthcache as I made my way down the South East today.

I have been here many times before, but never got around to doing this earthcache.

It was pretty overcast here today, but the lake still looked blue. That due works a treat!

Thanks setsujoku for an interesting eathcache.

What a fascinating lake and such an incredible colour blue. Thanks for this earthcache as it enhances my understanding of this area

Found with Salorm.
Nice brisk, windy day
Beautiful blue colour

TFTC setsujokuWe found your cache Blue Lake today.
We are camped in Penola for a week or so, caching and sightseeing. Today we headed out to Kalangadoo to attempt the wine bottle and glass and any other caches we came close to. A great day out on a reasonably sunny day.
Find number: 15388

As to why the Lake changes color we really have no idea. We did Google to get an answer but we would like to put forward that the Tourism people use a lot of dye. This in turn attracts the Tourists during the summer months. Then the dye loses kits potency and the water reverts to normal.

It seems implausible but why not?

With the Airshow in full swing in our home town of Lara we planned a weekend away in Mount Gambier to get away from the craziness and noise. After a big drive this morning/afternoon we thought the walk to the top and a visit to Centenary Tower was a good way to to get the legs working again after over 4 hours in the car.
By the time we returned to the car the sun had gone down to much so the lake was in shade so we decided to return again tomorrow in the bright sunshine as the day was expected to be a much warmer and sunny day.
Today we returned and we are glad we did. The lake was so blue compared to yesterday in the shade.
We have quizzed the whole family on their opinion about the cause of the lake's blue colour. They all agree that it has something to do with the sky, since we observed the water to be a brilliant blue while the day was bright and sunny. When the clouds came out and the day became overcast, the lake's colour was far less intense. When posed with the question of why other nearby lakes do not look the same, they agreed there must be more to it than just that. We also read about another local lake that used to show blue colouring, but no longer does. Here are a few suggestions that we came up with...
- perhaps there is a microorganism present that influences the colour. It could be less active in the winter months and has perhaps died off completely in the other lake that is no longer blue
-maybe there is something present, like a mineral, in the water from the volcanic rocks that becomes more concentrated in warmer months.
- looking at other lakes around the world, it seems that the clarity of the water influences the colouring. Extremely clear water may be allowing light to penetrated further and increase the amount of blue light refracted by the lake. Perhaps the clarity of the other nearby lack has been altered, stopping it from behave the same way now.

Thank you setsujoku for the Earthcache this is a place I have always wanted to visit

We had been looking forward to our visit to Mount Gambier for some time. We were very keen to make the walk around blue lake and read about the geology and history of this area. The volcanic crater lakeshere are outstanding and varied.
On our visit, the lake was a deep blue under a grey sky. We can imagine it would be a brighter blue on a blue sky, sunny day in the middle of summer.
We would also love to be here in late November when the leak changes from grey to blue.
We have sent our answers to the CO.
Thanks setsujoku
Domsky

Ocw the Bebes.

What an amazing sight this lake is when blue.

Answers sent by the Bebes.

OCW PelDroedGwin and geodog Peppa

Such a stunning Jake, we thoroughly enjoyed our morning walk here.

Answers sent to CO.

I think the blue colour could be due to the fact that it’s a true blue Aussie lake !

Tftc

Found on our travels through the area, heading to Portland from Millicent today. Stopped past for a geology lesson and to take in the views. Great location which is always impressive to visit when passing through. Answers sent to CO, cheers.

Find #5143 on 31 Jan 2023.
TFTC setsujoku!

I have visited the Blue Lake on a few occasions before when passing through Mount Gambier but doing this earth-cache focused my attention on various aspects of its geology etc. Thank you for this cache which prompted me to make another visit.

Such a beautiful spot!

Complete as team effort with mackay_geocaching. Answers sent to CO.