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My Yachting Adventures
Below is a list of links to the main pages about my yacht, Catlypso and My Yachting Adventures:
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  • My Yachting Adventures.
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    "Gordons Bay (Thommos) is as boring as bat shit"
    JD Reef (North)
    In October 2017, two new artificial reefs were installed off Royal National Park on the southern side of Sydney. This was organised by NSW Department of Primary Industries. It is intended for fishing, but there is nothing that prohibits scuba diving on it as it was paid for by the Transport for NSW Port Botany Boating and Fishing Infrastructure Fund (which does not appear to be from monies from fishing licences. It is said to be the largest artificial reef complex in Australia, but this seems to me to be a very loose interpretation of what constitutes a reef (see later).

    The reef has been named JD Reef. This is named after John Dunphy who apparently owned the Australian Shimano rights.

    The reef is in two sections, the northern one and the southern one (as they call them). The centre of the northern reef is located 540 metres south-east of Barrens Hut and the southern reef is 950 metres south of Barrens Hut (and 610 metres south-west of the northern reef.

    These reefs have been constructed in a very strange way. Rather than put all the structures together or even very close to each other, they are in a pattern, well separated from each other. Each reef structure is a Greek cross shape, that is, each arm is the same length. Each one is 100 metres east to west and 100 metres north to south.

    Each reef structure consists of 18 modules. The modules are pyramid shaped concrete structures (sort of like an Eiffel Tower), four metres square and five metres high. They weigh 25 tonnes each. Ten of the modules have steel structures bolted to one side that increase their height to nine metres. They are basically hollow structures that have lots of large spaces inside.

    Each reef has five parts. The middle part has four modules. The parts to the north and south (probably about 40 metres away), also have four modules. The parts to the east and west (also about 40 metres away) only have three modules. The modules in each part are about 7 metres away from each other. See the diagram below.

    JD ReefJD Reef
    The location of the two parts of the reefThe layout of the northern reef. The southern one is similar.

    Each reef is about 900 metres from the shore. The northern one is centred around S34⁰ 05.659' E151⁰ 10.657' (datum WGS84). In November 2017, about four weeks after the reef was finally all in place, we went out and decided to have a look and see what we could find. We motored to the GPS co-ordinates above and at first could not find anything. However, after running around a bit we picked up a structure on the depth sounder. It was not all that big, two hits. At this time we had assumed that the reefs were constructed of closely packed modules. We expected to run over a solid reef for about 80 to 100 metres.

    JD Reef
    Geoff Ward with one of the structures in January 2020

    We went around and around and finally anchored on the only one we managed to find. The depth was 28 metres. We hooked in and then I and my buddy descended. The anchor was on a cross bar of one of the modules. We left it there. The modules are quite large, standing high. The sand around and inside the modules has been cleared out a bit, so it is deeper there than the surrounding sand. Since then they have sunk a bit more into the sand I reckon.

    From the map above of the northern reef, we think that we were anchored on the western most section. Some of the modules also have steel poles attached to the cross bars, extending the height by a few more metres. One of the modules here had one attached. From the module were descended on, we could see another one about 7 to 10 metres away. After swimming round, we spotted a third module.

    We swam out away from each of the modules as far as we could before losing sight of the module. We did not see any more. The modules already have some growth on them, small barnacles were all over the concrete surfaces. There was not much fishlife around, although there were plenty of small flathead on the sand. Inside some of the modules were a few fish. You can swim right inside them.

    JD Reef
    One of the centre section's structures showing the rope I put on it

    As mentioned, the depth of this reef is about 28 metres on the sand. This limits your bottom time considerably. Although there was not much fishlife around, I can imagine that once the modules have more growth on them, they will start to attract more fish.

    We dived here now to see what they looked like so that when we come back in six or more months (well, it was much longer), we could compare them to when they were new.

    In January 2020 we decided to dive them again. We ran around with the depth sounder and easily found the ones near the GPS mark. We found some more to the south so decided to anchor there as we then knew there were more to the north.

    Once on the bottom, I saw that there were four structures here. I swam out a bit from the one we were anchored close to and saw the shadow of more. I then tied off the rope I had with me and ran out towards the shadow. Here there were four more. I tied off the rope. See the photos.

    JD Reef
    Another photo of one of the structures

    After the dive we ran around north of the GPS mark and found more. This leads me to think we anchored on the southern section, dived to the centre ones. Next time we will connect more up.

    There were a lot of small fish like mado around the structures, some yellowtail on the surface, but no fish worth catching. We saw a few non-edible crabs and even a crayfish. There is a lot of growth on the structures, including kelp. There were nudibranchs on there too.

    JD Reef
    Shows how close the structures are to each other in the group of four

    We plan to go back again within a month.

    Finally, it should be noted that this reef was established for fishing, so if you go to dive here and there are fishers on the reef you want to dive, you should go somewhere else. Generally, we intend to only dive the reefs on weekdays when there are hardly any fishers around.

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