Most of the dive sites at Heron Island are located on the eastern side of the fringing reef that surrounds Heron. Coral Cascades and Tenements 1 are sites located towards the southern end of the eastern reef. On my trip there in June 1989 and later in October 1989 for the Heron Island Dive Festival, I did this dive three times (always in the same direction).
Most of the dives at Heron Island are (used to be?) drift dives. Basically you start at one mooring and the boat moves to another one (sometimes two or more sites along) and ties up to that mooring. You drift along in the tidal current and when you pass each mooring you check to see whether the boat is there. If not, you keep going till you reach the correct one.
|A map of the dive sites of the northern side of Heron Island|
Click to enlarge
Note this map was drawn in 1990 by Clarrie Lawler - used with his permission
Coral Cascades is located to the north-west of Tenements 1 and is roughly east of the middle of Heron Island itself. Coral Cascades has a mooring that is on top of a bommie. This is the first of six bommies that are located in a row parallel to the main fringing reef wall.
|A very rough map I drew of Coral Cascades to Tenements 1 in 1989|
Note depths are in feet - Coral Cascades is at left
Once at the bottom of the mooring, you drop to the bottom of the bommie and head south-east. The depth here is about 15 metres. You should swim in between each of the bommies as you go, like a half a figure 8. The main wall has three small indents in it along the section opposite the bommies and it is wroth going over near the last bommie to examine one or two of them.
As the currents are normally never too strong, you should be able to do this without any problem. The bottom of the wall is about nine metres. After the wall, head out to about 18 metres and you should see some white-tipped reef sharks and perhaps some eagle rays. The bottom out here is sand with small coral outcrops.
Head back to the wall and you will see another indent and further along, one more. This one is very interesting, it heads right up into the main reef getting to about five metres or so. It is a bit narrow and windy, but well worth exploring. It ends in an upside-down Y shape with another passage off that may lead to another indent (I did not explore that one).
On my dives here I saw the most turtles I have ever seen on a dive. On one in June 1989 I saw at least 10 separate turtles. You should also see long-finned bannerfish, batfish, flutemouth, giant Maori wrasse, fusilier and sweetlips.
Once back on the main wall, continue with the current. Just past here the wall heads a bit to the south and creates a sort of bay. A ridge comes out in front of you and there is a tunnel (swim-through) through it. This is wroth looking at.
You are now at Tenements 1 and there is a large bommie off the wall that has the mooring on top. You should be able to see the dive boat there. Off the main bommie there are a few smaller ones. Spend the rest of the time exploring around the bommies.
Once again, an excellent dive.
Note this article was written in 2008 so my memory may be a bit out with some aspects of the dive site and things may have changed in the almost 20 years since I last dived there.