Robert's Ramblings

Last week a lucky few of us had the chance to dive the AV Ulonga.

The AV Ulonga was a Murray River paddle steamer converted to be an ocean-going cargo vessel. She sank in 1976 in around 38m of water about 10 nautical miles off the coast of South Australian's Fleurieu Peninsula. At over 33m in length with some penetration, she makes for a fantastic dive.

Pictured above on the descent are Alexius, with camera at the ready, and Ken. Notice the extra tanks we all took down for the dive. I'll let you guess what's in them!

For more information on the history of the AV Ulonga checkout Steve Reynold's article at http://www.mlssa.asn.au/nletters/march2005.htm

Until the next post, take care out there and keep diving ( if that's what you do! ) ...Robert

Photo: Robert Rath C5060 1/500s at f/4 ISO200 Inon UWL100-28AD Lens

The Ex-HMAS Hobart is one of Australia's best naval wreck dives. This Adam's class guided missile destroyer was sunk here in 2002 as an eco-tourism draw card.

At over 130m long there's a lot of wreck to dive on. Much of the wreck is in the 15-25m region which gives lots of bottom time. Still plan at least 10 dives to see it properly!

This photograph was taken in one of the engine rooms at around 23m.

As my first 'fun' dive for the year and my first dive on the Hobart with my camera, it was a fantastic way to kick-start 2008.

Until the next post, take care out there and keep diving ( if that's what you do! ) ...Robert

Photo: Robert Rath C5060 1/30s at f/6.7 ISO200 Inon UWL100-28AD Lens

We recently acquired a pre-loved Roland HP1500 digital piano at a real bargain price.

The real price in time and effort, however, proved to be another matter altogether. This piano was plagued with sticky keys. The previous owner claimed that two keys 'could be temperamental'. Once home, I could easily get eight keys to stay down permanently.

An hour later we had the piano entirely in pieces, with every single key mechanism removed.

Yes, all 88 of them.

Another hour later everything was cleaned and re-greased ('O'-ring grease worked a treat here) and I was ready to re-assemble. This is when the fun began!

Notice the grey PVC guide posts in the photograph. These are meant to be a perfect non-interference fit inside the keys. Too sloppy, and the key wobbles sideways. Too tight, and the key gets stuck. Like Baby Bear's porridge they need to be 'just right'.

As I replaced each key mechanism I tested the clearance. Even though only a few jammed, nearly a third were a little too tight and dragged the key action. Four hours of testing, filing, testing and filing every single guide post saw the job finally done.

Once again the piano felt beautiful to play.

So why did the keys become sticky? The keys may have deformed over time, but I suspect the PVC guide posts are to blame. Over time they may have swelled as a reult of absorbing solvents from the grease.

This is exactly the same reason why we use silicon-based grease for our camera housings. Having re-greased the keys using silicon 'O'-Ring grease, our piano should feel great to play for many years to come.

Until the next post, take care out there and keep making beautiful music ( if that's what you do! ) ...Robert

Update 2008-11-10 Response To a Received Email

I had no access to the service manual so simply undertook the task with screwdriver in hand and enthusiasm. I do remember that removing each and every key mechanism took a bit of knack and practice but I don't remember it being too difficult.

To clean the contacts (see photo ContactMech), I removed the rubber contact mechanism and cleaned both the carbon inserts and PCB contacts using methylated spirits and lint free optical tissues then reassembled.



The big job was the PVC guides (se photo PVC_Guides). This required very carefully sanding the outside edges of the guides with fine grade wet and dry emery paper then carefully cleaning with lint free tissues and then checking for fit. By making small changes and regular checking I effectively crept up on the correct fit. I set it to the barest perceptible drag with no slop.



Re-greasing (see a clear looking grease on the edges of the guides in the photo). Re-greasing required removal of all the old grease and the application of a small amount of silicon based grease. I used o-ring grease normally used to lubricate the silicon o-rings using in underwater camera housings. The key is the grease must not be petroleum based to avoid it being absorbed by the PVC and expanding.

... Robert

This sculpture of these beautiful creatures, 'Whales x 2' is the work of Terrance Plowright and can be found at Cockle Bay Wharf in Sydney's popular Darling Harbour.

I have been captivated by the humpback whale, Megaptera novaeangliae since seeing the amazing photography of Tony Wu from his recent trip to Tonga. His photography of these incredible creatures during the calving season is simply stunning. Please visit his site and be prepared to be gob-smacked!

Until the next post, take care out there, keep diving ( if that's what you do! ) ...Robert

Photo: Robert Rath EOS40D 10mm 1/40s at f/4.0 ISO3200

So why did the shark say meow? Because it was a catshark of course! I found this Varied Catshark, Parascyllium variolatum, while diving Whalebone Caves in Encounter Bay a few weeks ago.

Although found in a wide variety of Southern Australian habitats, little is know about this normally nocturnal shark. Fortunately for me this guy was up late. Unfortunately, trying to take the photos through gaps in the kelp made it hard to get a clear shot.

Whalebone Caves is another one of my favourite South Australian shore dives. Not very deep and only a stroll from the car park, this dive is like being in an aquarium. With an intricate maze of tunnels, caves and swim-throughs carved from the limestone sea-bed, this little place is fun to explore or just to hang out in at the end of a day's diving.

Until the next post, take care out there, keep diving ( if that's what you do! ) ...Robert

Photo: Robert Rath C5060 1/60s at f/3.5 ISO100 Lens UCL165AD Macro, Inon D2000 Strobe

This stunning looking creature is also the prize of many great seafood chefs. The King Scallop, Pecten fumatus is highly prized by the commercial fishery industry in Southern Australia.

Also known as the Southern Scallop, the Tasmanian Scallop or the Commercial Scallop, they can grow to over 14 cm across and live for just as many years. Scallops are filter feeders, living on plankton and other organic debris and are common to all our coastal waters.

This photo was taken on a night dive during my last Open Water course over in Edithburgh. It's fun to leave the students on the jetty, then come back to them with photos of what they'll soon be experiencing for themselves.

Until the next post, take care out there and keep diving ( if that's what you do! ) ...Robert

Photo: Robert Rath C5060 1/30s at f/8 ISO200 30mm, Lens UWL100-28AD, Inon D2000 Strobe

This weekend's get-away took us to the Flinders Ranges in South Australia's mid-north.

How lovely it was to sit by an open camp fire, stare into the heavens and not have to worry about getting into a cold, damp wetsuit.

In all of the beauty this place has to offer, there is nothing like the feelings invoked by a starry night in the outback.

I hope this image gives a sense of the sky we never get to see in our suburban world.

Until the next post, take care out there and keep staring into the heavens ( if that's what you do! ) ...Robert

Photo: Robert Rath EOS40D 160s at f/8 ISO1600 10mm

I just love this sleepy little town with its world-famous jetty. Many times though, I find myself teaching a group of new divers when that magic photo opportunity literally swims on by...

It was near the end of their fourth open water dive. I was leading the way back under the jetty while Alexius took care of the rear. In the distance, just out of vision there appeared a very large shadow which was not in a place I expected one to be. I realised it was moving and it was very, very large. A moment of fear, then a moment of excitement as the shadow turned back towards us.

Out of the gloom swam the most magnificent, majestic and certainly the largest stingray I have seen in nearly 18 years of diving. At around 2m in span and over 4m in length this Smooth Stingray, Dasyatis brevicaudata, glided through the pylons with both precision and grace. I turned and swam alongside for a few moments before leaving it to glide out into the sunlit water and disappear into the distance.

This was a magical experience that I may not have appreciated as much if I had been staring into the viewfinder of my camera. After the dive, it was wonderful to share the experience with my students, some of whom much to their chagrin had been looking elsewhere for the entire encounter.

Today was a wonderful reminder of why we go to all that effort to put ourselves under the waves: to bring back treasured memories like these.

Until the next post, take care out there and keep diving ( if that's what you do! ) ...Robert

Photo: Robert Rath EOS40D 1/250s at f/11 ISO400 10mm

August 28, 2007 and we were treated to a most wonderful evening show. For around 45 minutes, the moon became red as it passed through the Earth's shadow.

This photograph was taken from my back lawn in competition with Adelaide's night sky.

Total lunar eclipses come in groups; usually we can observe two or three during a period of a year or so followed by a few years without any.

Lunar eclipses are visible from the entire night-time hemisphere of our planet. Because of this they are more frequently observed and seem to be numerous. They are, however, three to five times less frequent than their spectacular solar eclipse counterpart.

Until the next post, take care out there and keep staring into the heavens ( if that's what you do! ) ...Robert

Photo: Robert Rath EOS300D 1.6s at f/5.6 ISO1600 300mm

The Potato Cod, Epinephelus tukula, is one of the largest members of the groper family. Cod Hole, out on the Northern Great Barrier Reef, is renowned for its family of curious Potato Cod who make this a special location for all who visit.

This was our last dive of the trip and we were not disappointed. It was a beautiful, picture-perfect dive. Big cod, sharks, rays and the most amazing coral gardens. We lingered here for as long as we dared as the current became stronger and stronger. Finally we decided it was time to return to the boat.

As all divers are taught we had done the right thing and dived up-current during the dive. By the time we decided to end the dive the current was so strong we could no longer make any headway anyway.

The swim back to the boat took only a couple of minutes and as we neared I could tell we only had one shot. Racing in at 6m, we caught the first shot line on the port side of the boat. The current was so strong now it started dragging us to the surface. Still hanging on to the port shot line at 3m we grabbed the starboard line of the deco-bar and there Jennifer and I stayed locked together flapping wildly in the current. A minute later we had worked our way up to the starboard ladder and back on board. Hearts racing, adrenalin pumping - but smug at the fact that we did not have to be chased all over the ocean by the tenders like some of the other divers - we said our farewells to the Potato Cod of the Cod Hole!

Until the next post, take care out there and keep diving ( if that's what you do! ) ...Robert

Photo: Robert Rath C5060 1/30s at f/6.7 ISO200 Inon UWL100-28AD Lens and D2000 Strobe

This Lionfish or Red Firefish, Pterois volitans, was a real poser circling the top of the Pinnacle. Yes, another cliché photo but one begging to be taken!

As mentioned in a previous post, Lionfish are common to the Indo-Pacific region and considered every bit a part of our tropical waters. Its new arrival in the U.S.A. however is not welcome at all since being introduced by the aquarium trade back in 1992. Having no natural predators in other parts of the world means this beautiful creature has become an introduced pest to our friends bordering the Atlantic Ocean.

Until the next post, take care out there and keep diving ( if that's what you do! ) ...Robert

Photo: Robert Rath C5060 1/125s at f/5.6 ISO200 Inon UWL100-28AD Lens and D2000 Strobe

This beautiful nudibranch, Chromodoris elisabethina, or possibly , Chromodoris annae, was one of several different species we found at Pixie Pinnacle during our Minke trip.

The distinctive broken black stripe down the back is usually associated with ... elisabethina. See my previous entry for Chromodoris annae which clearly has no black markings. Please let me know your thoughts on the identification.

Pixie Pinnacle is an amazing site near Ribbon Reef #10. The pinnacle itself presents an amazing array of life and will often be the most attractive part of the dive. It is worthwhile though exploring the scree and rubble at the pinnacle's first base where we found a diverse world of small critters including Nudibranchs and Mantis Shrimps.

This little guy was down in the scree and rubble at 20m and reminded me of PNG "Muck Diving".

Until the next post, take care out there and keep diving ( if that's what you do! ) ...Robert

Photo: Robert Rath C5060 1/90s at f/4.8 ISO200 Inon UCL165AD Macro Lens and D2000 Strobe

We have just returned from an absolutely wonderful trip to the Ribbon Reefs on the Great Barrier Reef. Three days of diving with Minke whales, reef fish, pelagics, sea turtles and even the odd diver have left us longing for the warm seas again now that we are back in Adelaide.

This one particular Minke swam straight towards me on several occasions, each time coming a little closer before bearing away. It was a magical experience, and at times I felt I almost wasted it being behind a camera!

Minke whales, Balaenoptera acutorostrata, visit the Ribbon Reefs every year during June and early July on their yearly migration. They are beautiful, inquisitive animals and actually seek out encounters with snorkellers and divers alike.

We dived from Mike Ball's Spoilsport and were impressed with their Minke education program as well as their adherence to a strict protocol used for Minke encounters.

For more information about Minke whales please visit http://www.minkewhaleproject.org/

Until the next post, take care out there and keep diving ( if that's what you do! ) ...Robert

Photo: Robert Rath C5060 1/90s at f/4.0 ISO200 Lens UWL100-28AD

I can't believe it has been nearly a month since my last post! This last weekend we were in Edithburgh again with a group of nine Open Water students. Even with 11 degrees, wetsuits and less than 2m visibility, they were a fantastic and enthusiastic group. Well done!

Despite the teaching, the cold and poor visibility, we still managed a few "fun" dives and captured some lovely images. The photo for this post is a very awesomely cute Southern Dumpling Squid, Euprymna tasmanicas.

The amazing thing about the Southern Dumpling squid is that it produces light from an organ in its gill cavity. This organ contains bacteria that glow in the dark, and the dumpling squid uses this light to hide its silhouette from below by exactly matching the light from above. Very impressive camouflage technology!

On Sunday afternoon, my old mate David Bryant from Seapics http://www.seapics.com.au/ joined us for a dusk dive after having driven non-stop from Melbourne that morning.

David and some of his friends have come over to dive with the Whyalla cuttlefish, so it was a great chance to catch up and dive together again after some 12 or more years.

Until the next post, take care out there, keep diving ( if that's what you do! ) ...Robert

Photo: Robert Rath C5060 1/45s at f/8 ISO200 Lens UCL165AD Macro, Inon D2000 Strobe

Night dives under Edithburgh jetty mean seahorses. Lots and lots of them! Almost all of them will be the Short-Head Seahorse, Hippocampus breviceps. No matter how patient I was, this little one would not look at me, so this is the best of a batch where turning away means 'you can't see me'.

Two wonderful days of diving here have left me with quite a collection of new photos, so stay tuned for more.

Until the next post, take care out there and keep diving ( if that's what you do! ) ...Robert

Photo: Robert Rath C5060 1/90s at f/4.8 ISO100 Lens UWL100-28AD, Inon D2000 Strobe