What it’s like to swim with giant Australian cuttlefish

Every win­ter along the coast in Upper Spencer Gulf Marine Park between Fitzger­ald Bay and False Bay near Whyal­la in South Aus­tralia, thou­sands of giant Aus­tralian cut­tle­fish con­gre­gate to mate.

Swim­ming out over the rock ledges and weed you sud­den­ly see a flash, like sun glit­ter­ing off a metal­lic object in the distance.

Swim­ming towards this glit­ter, it’s not long before you realise you are sur­round­ed by huge yet incred­i­bly grace­ful giant Aus­tralian cut­tle­fish – the larg­er males the size of a medi­um sized dog, the body mea­sur­ing over 60 cen­time­tres long and weigh­ing 5 kilograms.

Despite their huge size, these crea­tures hov­er around effort­less­ly much like a space­craft in orbit. Yet if threat­ened they can shoot water through their siphon and move through the water back­wards at light­ning speed.

In an area the size of the aver­age rum­pus room, you will see 20 to 30 indi­vid­u­als. You will wit­ness large males putting on incred­i­ble colour shows pul­sat­ing through all the colours of the rain­bow at the blink of an eye.

Small males will come in close, pull in their ten­ta­cles and change colour to mim­ic a female – when the large male isn’t watch­ing the small cross-dress­ing male will swoop in and mate with the female.

At first the sheer size and rapid colour-changes of these crea­tures is intim­i­dat­ing, yet after a few min­utes you realise that they are obliv­i­ous to your pres­ence. There is one thing on their mind – procreation.

The best spot for young fam­i­lies to expe­ri­ence the giant Aus­tralian cut­tle­fish is Stony Point, about 20 kilo­me­tres north east of Whyal­la, where there is easy access via a board­walk to shal­low water. The next best spot is near­by Black Point where you will also find shel­ter from a north or north-east­er­ly wind on the north-west point of Black Point.

Giant Aus­tralian cut­tle­fish start to con­gre­gate to breed in mid-May but the best time of year to expe­ri­ence them is June and July when the breed­ing sea­son is in full swing.

They are active day and night, but the best time to swim with them is nor­mal­ly in the morn­ing before the winds pick up in the afternoon.

The breed­ing areas off Stony Point and Black Point have an aver­age depth of 4 metres, so as long as the vis­i­bil­i­ty is at least 4 metres you will eas­i­ly see giant Aus­tralian cut­tle­fish while snorkelling in the shal­lows close to coast. 

If you’re care­ful to move slow­ly, you can get up close with­out dis­turb­ing the cut­tle­fish. In fact, they seem obliv­i­ous to peo­ple as they go about their activ­i­ties of out­smart­ing oth­er cut­tle­fish to find a mate.

In the win­ter months, the water is very cold so a well-fit­ting full 5‑millimetre or 7‑millimetre wet­suit with hood, gloves and boots is the way to go. If you haven’t got your own gear you can always hire it.

Snorkelling is safe along this bit of coast but you do need to be care­ful when enter­ing water over rocks and boul­ders, as they can be unsta­ble and slip­pery. Stony Point has a board­walk down to the water and a waist-height chain to hold onto for sup­port, mak­ing it the safest point to enter or exit.

I’ve been lucky enough to dive with the giant Aus­tralian cut­tle­fish many times since my first vis­it in 2005. In fact, my first dive trip to expe­ri­ence the giant Aus­tralian cut­tle­fish con­gre­ga­tion and their incred­i­ble show of colour inspired me to buy my first under­wa­ter camera.

To wit­ness some­thing so awe-inspir­ing and spe­cial in my own back­yard, which peo­ple trav­el from all over the world to expe­ri­ence, keeps me com­ing back. I’m always after ​‘that’ spe­cial image that shows one of the many colours, tex­tures and behav­iours of these mag­nif­i­cent creatures. 

The sheer num­ber of cut­tle­fish makes the Whyal­la breed­ing aggre­ga­tions unique, not just in Aus­tralia, but the world. Swim­ming with Whyalla’s Giant Aus­tralian Cut­tle­fish con­gre­ga­tion is a glob­al­ly sig­nif­i­cant unique nature-based tourism expe­ri­ence in our own backyard. 

Want to see it for your­self? Book a guid­ed ses­sion to swim with giant Aus­tralian cut­tle­fish in Upper Spencer Gulf Marine Park near Whyal­la this winter.

If you’d rather learn about the under­wa­ter crea­tures hang­ing out in SA’s waters from the com­fort of dry land, check out our blogs about sea drag­ons, blue dev­il fish and squid.

(All images copy­right Carl Charter)

This sto­ry was orig­i­nal­ly post­ed in July 2015.