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 by damien

WW2 Wreck Dived – SS Wollongbar II

It’s not every day you get to dive a WW2 shipwreck off the NSW coast, so when you get to do it with 50m visibility it’s something special. Yesterday we dived the shipwreck of the SS Wollongbar II, which was sunk by a Japanese sub in 1943 with the loss of 32 lives. She now lies in 92m off Crescent Head, quite broken up after two torpedo hits but covered in artefacts and sea life including grey nurse sharks, king fish and huge schools of jewfish.

My dive buddy was Ben Morgan, our dive was 92m for 34min resulting in a 184min dive time; so our many thanks goes out to our boat team (Dean Coleman and Peter Tibbits) for their hard work and effort on a long day. I can’t forgot previous team contributions from Geoff Cook, James Dibbs, Dean Drinnan, Scotty Willan, Peter Fields and Warwick Jones. Support from Fishrock Dive as always is excellent, Bia & Peter Yarwood and Jon Cragg before that. Enzo Andreano deserves recognition too, as without him Ben Morgan would not of made it to SW Rocks after a car breakdown.

The shipwreck was originally reported by to Heritage NSW in 2019 and surveyed subsequent to that. COVID, injuries, weather and a stupid road cycling event thawted our earlier plans to dive the wreck. For those interested in the story, the Heritage NSW Information Sheet is a good read. If you’re more technical and/or want more info on the site, the Heritage NSW Survey Inspection Report is more comprehensive. Access to the site for diving will typically be either 17nm up from Port Macquarie, or ~20nm down from South West Rocks. GPS position for bow and stern marks are below, we dropped our shot just south east of the north mark (ie the stern) which was right on the boilers. It’s a long and wide target running mostly inline with North-South current.

Bow – North: S 31˚ 12.566’ E 153˚ 06.220’

Our Shot Drop: S 31˚ 12.574’ E 153˚ 06.223’  (Mark 147 on the plotter picture below)

Stern – South: S 31˚ 12.593’ E 153˚ 06.219’

If you’re interested in diving the shipwreck I’d highly recommend you contact Fishrock.com.au, their larger boat is perfectly suited for the long run and extended time on site that its required to dive the wreck; they’re also great people and intimately familiar with the area and technical diving operations.

Technical difficulties with my rebreather limited my capability to shoot photos, so all photo credit goes to Ben Morgan with the trusty GoPro.

 

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 by damien

Carbon Monoxide Oxygen Analyser

Given the ridiculous cost of diving oriented CO analysers (particularly when put against those available for industrial safety), I thought I’d put together a dual gas analyser to simuilataneously test for both oxygen (O2) and carbon monoxide within diving gases. The solution uses an affordably priced CO sensor, which is factory calibrated (estimated life span greater than 2 years, resolution 1ppm with 0-1000ppm range). The O2 analyser part follows the well traveled path of using a standard R22D sensor, which I removed from my CCR after 12 months but stil has lots of life left in it.

The microprocessor is an ESP32-C3 development board with a basic C program that uses the Arduino framework. You can download the code, which I’ve written using VSCode & PlatformIO however, it’s pretty portable to whatever IDE you want. As always, the code could do with some optmisation but I’ll leave that for another day… The display, 16-bit ADC and CO sensor all use the I2C bus so wiring is relatively simple. The system is internally powered by an 18650 battery in a UPS module, which is externally rechargeable via an exposed USB-C port.

All the electronics are housed within a cheap Pelican style case (which seems surprisingly half decent), with a 3D printed assembly providing some structure to hold the parts together. You can download the STL or Fusion model.

WARNING: This is a cheap DIY solution, coded by a tight ass and poorly tested. It uses a CO sensor that has a bold disclaimer that it should not to be used for life support. Please consider these things and the value of your life before deciding to make your own unit. This analyser is not a commerical solution.

Parts List

 

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 by damien

Boat Anchor Retriever

I know there are a lot of boat anchor retrievers on the market, though I’m sharing a cheap rope ascending device that has served our specific use case nicely. The problem was that the usual marine devices didn’t work well, or at all, with the 8mm silver shot lines we prefer for deep wreck drops. We only use a variety of shot lines, with variable chain lengths and anchor sizes so the loop/ring types that run through the chain didn’t suit either.

We’ve found this rope climbing ascender however has been great for several years now, and seems to run down the line with little resistant, but cam locks on the return pull very well (even on the cheap, slippery 8mm line). I was skeptical as to whether it would hold up in the salt water, but it’s been going strong for years with no maintenance at all.

For under $20, it’s hard to beat as an anchor retriever – though personally I’d stick with a more reputable brand for rock climbing.

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AIS SMB
 by damien

AIS Enabled SMB Beacon

For years I’ve wanted a solution that can provide real-time tracking for divers underwater, now we have a one. AIS is a marine radio positioning system that at is simplest, broadcasts a vessel’s GPS position for other to track. The system however can be leveraged to send the non-emergency position of other objects drifting in the ocean such as fishing nets, or in our case divers underwater. The signal is then received by the boat’s VHF radio and displayed on the chart plotter.

The conceptual solution is relatively simple; get a low cost Chinese fishing nets AIS beacon and attach it to an SMB that is deployable by divers drifting in the ocean. The problem until recently was putting this in a form factor that isn’t a burden to carry and/or use on deep technical dives. The issue we faced originally was finding a AIS electronics solution in the right form factor, most were large and didn’t suit small diameter pressure housing used underwater. Mounting the antenna in the vertical seam of the SMB was also presented problems (mostly reliability over time).

More recently, low cost and narrow form factor AIS beacons have appeared on the market. I recently took one of these, did some minor tweaks to the antenna, extending the wiring and folding it back on along the board to make it short. I knocked up a pressure rated housing and like magic you have an AIS enabled SMB.

Usage is simple…turn the unit on pre-dive, validate signal on boat plotter, seal canister and dive. Divers then launch the SMB from the bottom as per normal and when the SMB reaches the surface the GPS signal is sent to the boat. The advantage is that the boat gets an active position signal from divers that may have hours remaining to surface.

The solution isn’t perfect, with these issues:

  • Range is yet to be tested and is likely compromised by the antenna being laid back against the battery and circuit board (versus sticking out the end on the OEM solution)
  • Size of SMB seems to matter; I purposely used a small one for initial tests though I’m planning to upsize this. The smaller SMB too 6-9lbs of negative weight to get the SMB erect
  • The AIS beacon I used doesn’t allow programming of MMSI and ping intervals
  • The AIS beacon I used doesn’t seem to be available anymore online, though similar one is here and allows programming MMSI

For interest sake we also carry the Nautilus LifeLine and housing PLBs on deep drift deco dives, but both require the diver to surface which could be hours if initial traditional SMB are not sighted by the boat. We’ve done drift dives in up to 5kts of current which is problematic to say the least. The AIS SMB is simply another tool in the bag to ensure the boat reacquires divers promptly.

AIS SMB Pictures
AIS SMB

 

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 by damien

MV Fairwind – Missing Crew Update

In 1950 when MV Fairwind was lost with all hands, the crew list and media reports listed 5 named Australians and something like “12 blacks”, “12 niggers” or “several PNG natives”. This has always pissed me off, so I’m real happy to play a small part in righting this.

Several years back I was contacted by the living family of Cecil Himogo, who advised me that he indeed was part of the missing crew of the Fairwind. Now 5 years later (and 9 after we found the Fairwind), Cecil’s grandson (Jeremiah Jeremiah) has been able to provide the names of 6 additional members of the crew.

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 by damien

Barge ’21’ – New Sydney Wreck-ISH

Shipwrecks are a funny thing, lure you in for a look even when you think they’re not going to be much chop. Starring at the multibeam scan we thought piece of wharf, barge, pontoon, even a cataraman yacht. With some ominous weather looming, we jumped in for a ‘quick look’, and found what we had expected – a scuttled barge/pontoon in around 57m of water.

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 by damien

WTF: SS Wear or What?

Is the shipwreck WTF actually SS Wear? I believe so, here’s why…

Identifying any wreck in 125m can be difficult, but the history behind the shipwreck named “What the Fuck” or WTF is confusing. Discovered by a Sydney Project team in 2006, the WW2 era wreck was originally identified as SS Iron Knight. Subsequent dives proved this to be incorrrect based on size and configuration, so the name WTF stuck. In more recent years, a case has also been made for it actually being SS Coast Farmer.

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