Snorkeling advice for Australia

As an Australian, I'd say Queensland, and the Great Barrier Reef specifically. That means you'd be staying in Cairns, Port Douglas or the Whitsundays, most likely. For snorkeling, you're best off visiting during the dry season (May to October).

Our snorkeling trip was disappointing. Cloudy water, the small chop and wind made the snorkeling hard. There was few fish and uninspiring coral reefs. The trip included 2 stops. I wouldn’t waste my time flying north to see the Great Barrier Reef. It was part of an Australia tour.

To start off, the reefs will be intact well past my children's lifetimes, so I am sure that you have plenty of time. All reefs in the world do have bleaching events from time to time but do recover, as the GBR has done in Australia.
As the Great Barrier Reef is the largest in the world, you have plenty of places to choose to enjoy this natural wonder, depending on budget and time of year. There are also easily accessible coral reefs of the coast of Western Australia, most notably Ningaloo.
The majority of tourists choose to visit our GBR from Port Douglas or Cairns. The best time to visit is during our winter months as PD & Cairns are in the tropics and subject to cyclones and heavy rains in the summer months. If our summer is the only time available to you, then Ningaloo works or below Rockhampton at places like Lady Elliot Island

Look into Lady Elliot Island. We were there in July, and it was amazing.

https://ladyelliot.com.au

If you do a search for best snorkelling in the Great Barrier Reef, many sites will recommend Lady Elliot Island, which is why we chose it.

That said, healthy coral isn't doesn't have the vivid technicolour that you sometimes see in photos. It's more muted, with lots of greens and browns. The reef around Lady Elliot Island is very healthy.

https://simonmustoe.blog/what-does-healthy-coral-reef-look-like/
https://hakaimagazine.com/news/we-have-unrealistic-beauty-standards-for-coral-too/

Very good description of GBR corals above.

I was used to vibrant Caribbean corals from the last century before bleaching was a world-wide concern. I did have one good day (out of two snorkeling trips out of Cairns and Port Douglas) on the GBR. The corals are muted compared to what I was expecting. The fish and sea life on my 2nd trip were outstanding- made up for my coral disappointment due to my misplaced expectations.

If I was returning for snorkeling, I would be looking at Lady Elliot Island as suggested.

I was in Australia this last March/April. In April I went snorkeling twice, at the Whitsundays (from Airlie Beach) and from Cairns. I loved the experience from Airlie Beach. The water was clear and spectacular in shades of blue you couldn’t imagine. The fish, coral, etc. were easily visible and overall I would give the experience a 10 out of 10. The snorkeling trip from Cairns was not quite as pleasurable. The water was quite choppy and cloudy so it was not as easy to see the sea life. I would give it a 4 out of 10. I was there at the end of stinger season and wore a stinger suit that the tours provided. I think stinger season ends at the end of April and it would have been nicer to not wear the suit.

I'm not sure I'll get around to doing a trip report, but here are some of my photos from LEI, to give you an idea. (I don't have a professional camera or anything, so they aren't super high quality.)

https://www.amazon.ca/photos/album/up5h7-JPR6uqwXkZHWikDw

Note that the photos of the manta ray and the blue-spotted ray aren't mine. I included them in order to remember what I saw, and my own photos of those didn't turn out. Also, the octopus photo isn't the best. I got a lot of video of it, but I don't have more video storage available in my account. We spent about 10 minutes or so with the octopus. It was very exciting for me.

There are many companies that offer group boat trips from Cairns. A guidebook suggested to me that if you only have one day for a trip, you want to pick the biggest boat you can find, so that you don't care about the sea height or the weather. Also , high speed means more time at the Great Barrier Reef. We took a huge steel catamaran that leveled out some of the seasick-causing waves. (All these boats have bowls of seasick pills on the bar/snack counter.) I think it carried 100 or 200 guests. We moored to their proprietary barge, which has aluminum picnic tables (for the hot lunch/barbecue, included) that they hose off before they return to shore.

The point is, this is not the time to hug whales or mope about modern structure imposed on a Euell Gibbons experience. You're halfway around the world, and you want to have a successful day.

This barge also has stairs down to a bench where you sit chest-deep in water, to put on your flippers while seated! Then you step off to your snorkeling, which was outstanding. There are (extra cost) boat rides, submarine rides, and even helicopter rides for those with a large budget.

On the other hand from the experience related above, I purposely choose 2 different smaller boats for my excursions. I did not want to be on a large boat with several hundred who were not experienced snorkelers or divers. I booked two different tours from two different ports on two different days - as noted above, traveling all that distance from the US, I thought booking two days might "hedge my bets" a bit for actually getting out on the water.

One of the days I went out, the departure was delayed due to weather. Not just my boat, but the larger boats such as described above as well.

Neither approach is better than the other in my estimation. It depends on the traveler and the experience desired.

I would advise taking seasick medication before going out - no matter the size of boat. Meclizine, brand name Bonine, was recommended to me by my MD. I brought it from the US - it wasn't sold in Australia when I was there but I don't know current status. These medications are frequently more effective taken before hitting the water than after the effects of seasickness has begun.

Couple things...

• You are talking about an experience with Mother Nature here. It's important to remember that Mother Nature is not a Disney theme park, it's natural, unpredictable, unreliable, occasionally messy and complicated. That means, conditions can, do and will vary. Variable conditions include:
• Visibility - how clear the water is. If it's very clear, you'll be better able to see what's in front of you. If the viz isn't great (and on some days, it's not) you won't be able to see what's in front of you as well. You want nice, "gin-clear" water, but there's no guarantee of that, because many conditions can wreck visibility. That includes weather (has it rained recently? runoff from rainfall can easily wreck viz when you are close to land, but will have less impact on reefs further out).
• How many other people are around you (and what kind of people those are) - that can have a big impact on visibility and also the health of the reef. First-time snorkelers often do a LOT of damage to reefs. In many (most?) popular tropical resorts, the reefs are hurting badly because vacationers are dropped on the reefs, they immediately stand up on the reef, which kills the animals that compose the reef. I witness this pretty much every time I go in the water in a tropical resort destination. It happens every day, all around the world. It's tragic, heartbreaking, and incredibly frustrating to watch over and over again: people fly half-way around the world to see coral reefs, the first thing they do is stand on that reef, which kills it. You will see this almost everyplace you go.
• Honestly, most people will not notice the difference. They see complex-looking coral and some fish. It's pretty. They've never seen anything like it before - they've never seen anything at all underwater before, so they have nothing to compare it to, so many of them go home satisfied, happy with their experience - even if it was a mostly-dead reef, even if they contributed to its death by going there.
• Aside from vacationers standing on and otherwise physically touching reefs (which kills them), of course reefs worldwide are suffering from climate change and other human-caused troubles (agricultural chemical runoffs, pollution, rampant development, etc.). That said, they can still be magnificent to see. But...

The best way to enjoy a healthy, thriving tropical reef (in Australia or anywhere) is to avoid going to the places that are being loved to death: the popular, relatively easy-to-reach places that get more attention than is good for them. Many Caribbean reefs are in bad shape for all the reasons mentioned above, especially cruise ships, which simply put too many people concentrated in too few/small places, with careless operators taking out inexperienced visitors who have no idea what they are doing and don't even realize that touching coral kills it.

Snorkelers need to be comfortable enough in their gear that they can float on the surface without ever touching the bottom; they need to be able to put their faces in the water and keep them there, breathing through their snorkel - NOT stopping, standing up, putting their fins and feet on the live (now dying) coral. Alas, this takes a little practice to get comfortable with the gear, calming down and being able to do what your body will initially reject as crazy and suicidal: putting your face down in water and believing that you're not going to drown. Everyone initially has a strong natural survival instinct you have to get over, and this takes some time. Nobody should do this when they've just been dropped on top of a reef, yet that's what operators do. It's crazy, but common.

Avoid massive boats and huge "cattle boat" operators. Choose an outfit with small groups that teaches environmental responsibility. It may cost a few bucks more and there may be minor inconveniences (going further out of the way). It's worth it.

Just my 2 cents from a lifelong SCUBA diver.