Swansea Bridge

Lake Macquarie is the largest saltwater lake in Australia. It is located to the north of the New South Wales Central Coast and on the southern outskirts of Newcastle. The lake is connected to the Pacific Ocean by a channel that is crossed by the Pacific Highway at Swansea. The highway was the main link from Sydney to Brisbane until the late 1980s when a new section of freeway by-passed the area. About the same time, the single bridge across the channel was duplicated (a bit late considering the delays encountered here before).

The water from the ocean runs in and out of the lake with the tides. The piles of the two bridges, as well as the remains of older bridges (two I think), provide a home to an incredible amount of fishlife as the water rushes past. Of course, it is not possible to dive under the bridge during the flow of the tides (although you can do a drift dive past the bridge) due the extremely strong tides. There is a way to dive the bridge and this is to do it at slack tide (high tide).

This dive starts from what was the old punt ramp located on the southern (Swansea) side of the channel and the western side of the old bridge. The old ramp has been done up and looks quite different to how it used to appear. Coming from Sydney you take the first on your left after the lights in Swansea and from Newcastle turn right immediately after the bridge and right again (this puts you on the other side of the Pacific Highway heading back to Newcastle) and then take the ramp on your left. There is a boat shed for the Swansea Surf Life Saving Club here and you can park in the small car park behind it or on the street. You can also park on the eastern side of the highway, in the street parallel to the highway.

Swansea Bridge

It used to be that the idea was to arrive at the dive site about two hours after the published high tide time and set up your gear. I was told a formula to calculate the exact time to enter the water but it was too complex to remember and it did not seem to work on the day I dived it. On a small 1.2 metre high tide, I entered the water 1 hour 50 minutes after the published high tide when the tide looked to have almost stopped. However, the tide was still running in when we got in the water but it was not too strong and we could swim against it even though it took a bit of effort at times. We should have started about 2 hours 15 minutes after the high tide. The slack tide seemed to start about 2 hours 25 minutes after high tide and continued till at least 2 hours 50 minutes after the high tide. On a 1.7 metre high tide we entered the water 2 hours 25 minutes and there was a slight incoming current tide and slack was about 2 hours 45 minutes and only went for about 10 minutes or so. On another 1.2 metre tide, we entered the water 2 hours 20 minutes after high tide but the water was still quite strong (we entered at the behest of a local instructor who said it was time to go in). Even when we left the water exactly 3 hours after high tide, the tide was still coming even, albeit just a trickle. We should have entered the water at about 2 hours 45 minutes. This dive may have been affected by a very strong westerly wind which may have slowed/delayed the tide entering Lake Macquarie. The best bet from my dives here was about 2.5 hours but this has now changed. See next paragraph. I would still get there about two hours after the high tide as parking is limited.

Some of the pylons and fish under the bridge	An estuary cod, some bream a morwong and other fish under the bridge

In mid to late 2004, the Roads and Traffic Authority did some work on the western (north bound) bridge which was sinking. We dived there in August 2004 and the noise from the pile driver was very, very loud. They appear to have driven new piles into the sand, put in some bracing to other pylons and cross-bracing. They have also dumped a huge amount of gravel under the bridge and around the piles. This has made the area much shallower. Where it used to be over 13 metres, it now comes up to 7 metres, although it does drop to about 11 metres at the deepest. Interestingly, one pylon has had the gravel eroded out about 3 metres by the action of the current.

On dives since the work was done on the bridge, we entered the water 3 hours after a 1.5 metre high tide and it was not slack till 3 hours 35 minutes. However, at least on this dive it was not too strong even at the start. I have been told that the dive shop adjacent to the bridge (see later) has said that the high tide at the bridge is now later due to the shallowing of the water on the north-western side of the bridge. In February 2006 we again dived here on a 1.6 m tide. We entered the water at two hours 52 minutes after high tide but the current did not slacken till 34 minutes into the dive, that is, three hours and 25 minutes after published high tide. The comment from the dive shop appears to be true. Therefore, it appears that you should not enter the water here till about 3.25 to 3.5 hours after high tide at Fort Denison (Sydney Harbour). When you see the water start to slow up, enter the water and begin your dive. It used to be easier to judge this as there was a buoy that was right near the bridge and this would stand upright (rather than over at an angle) when the tide slackened.

Once in the water, drop to the sandy bottom from the ramp alongside the rocky channel wall. It is about seven metres deep here. Swim towards the bridge and you will see some shopping trolleys and once you are past the first bridge, cross over to the first of the pylons. It appears that someone has (at least in Feb 2006) strung a rope right across the channel that enables you to use it to assist your efforts, especially if the tide is still strong. Almost immediately you will see huge numbers of fish. The first species are normally luderick and bream and there are normally hundreds of each, excellent in size, swimming in between the pylons. Look out for the very large tarwhine (black bream) which resemble their cousins the silver bream. Continue over to the second series of pylons and you will see that these are much larger in size (this is because they hold the bridges' span opening machinery). Despite the current, you can get out of it by going behind the pylons and hugging the bottom. There is a large amount of rubbish on the bottom, mostly old pylons and pieces of bridge as well as pipes and other things. These offer protection from the current and a home to many species of fish as well as soft corals and sponges.

A close up of the estuary cod from the above photo

There are a couple of water pipes and a gas pipe that crosses the channel using the bridge and they go under water at the second pylon and come back up to the deck at the third pylon. In between the two pylons the pipe runs a bit above the sand and provides a home to an enormous amount of fishlife. I have seen huge mud crabs under the pipe and there are sometimes hundreds of red crabs on the pipe and on some pylons. Here you will see dozens of surgeonfish and I have even seen kingfish, a species normally seen in deep water, here. There are hundreds of red morwong and lots of the less common magpie morwong. On my first dive here I heard a strange noise and after a few seconds I figured out that it was the twin spans of the bridge opening to let a vessel through. When this happened, I signalled to my buddies and we lay on our backs and watched as the bridge opens above us and a catamaran sailing vessel powers though the now incomplete bridges. Fantastic.

Continuing across the channel under the western bridge and you may find a knightfish (pineapplefish) in one of the many pipes or under the concrete bases of the pylons (I have seen up to 12 in one location on the same dive) and there are sometimes huge dusky flatheads on the sand. Every pylon and piece of wreckage has dozens of leatherjackets hovering around. They include mosaic, rough, fan-bellied and yellow-finned species. In this area I have seen a small rough flutemouth and there a many octopus, both small and large, all over the place. The whole of the sand bottom is covered with thousands of eastern fortescue. The current should be starting to die as you reach the northern shore of the channel and you can surface for a quick chat. You will have been in the water about 15 to 25 minutes depending on the rate of travel. If you have crossed quickly, you can go back much slower.

As I mentioned above, the deepest part of the dive used to be near the pylons on the western side where the depth was over 13 metres. However, it is shallower now. Go to the eastern bridge and follow this on the way back to the southern side. On the way, cover the bits of the dive site that you missed on your way over as you zigzag back.

Kelly McFadyen under the Swansea Bridge

You will see some more species of fish, including some of the biggest yellowtail you will ever see and some juvenile snapper. In a couple of spots there are some places where stripeys and mados seem to live in huge numbers. You may see threadfin butterflyfish and you will certainly see old wives and eastern talmas. There are other species, one-spot pullers, girdled parmas and white ears. I have seen soles, hidden perfectly (well, almost) in the sand, and there are some very nice whiting near the shore.

As you go under the main span you will hear and then see power boats which rip through under the bridge at high speed. This is definitely one dive site where you do not follow what you were taught in your Open Water course, never surface if you lose your buddy. Likewise, on each dive I have been on the lookout for moray eels but have not see one, although I know others who have seen them.

Dive time is from 40 to 50 minutes, depending on the strength of the current. This is a great dive site, worth doing many times.

There is a dive shop, Aqua Zero, right next to the dive site for airfills before or after the dive.

This dive site is only two hours from Sydney (even less from the northern side) and can easily be done as a day trip. We do it on a Saturday and then head up to Stockton Beach for some four wheel driving and camp overnight in the dunes. Highly recommended as a dive site.