"I describe the pain as excruciating because the word comes from crucify, and that's exactly what it was — there's was no other way to describe it," Renshaw told NewsMail while recovering from stepping on a stonefish in late February.
The poisonous spine stabbed in between his toes and broke off, meaning he needed surgery to remove it.
Fortunately, paramedics got him safely from the beach to a hospital, and he's now getting back on his feet.
He's not the only one to have been stung before. A man who was stung in Fiji also described the sting as excruciatingly painful. His exact words to Australia's ABC News were:
"I guess I could best describe the pain as holding an oxy-acetylene torch on your foot, and then working its way up your whole leg over an hour or so, then smashing your leg with a sledgehammer every 10 seconds."
According to NatGeo, the stonefish stings with its 13 dorsal spines. These spines are capable of piercing human skin and injecting venom deep within the tissue.
You can see in this gif how the toxin shoots out on contact.
Stonefish don't use these poisonous spines for hunting, per NatGeo. They're purely a defensive strategy. The stonefish actually hunts via surprise attack. Much like the wobbegong shark, stonefish lie in wait for prey.
Then they quickly snap open their jaws, creating a vacuum that sucks their food in.
The deadly poison spines are just an added bonus on their backs.
If you do get stung by a stonefish (which would be understandable because they look just like the rocky reef until you're standing on one) ...
... there are some measures you can take.
You should firstly note that a stonefish sting can be deadly, so you'll need to act quickly. The Brisbane Times reports that stings cause "immediate pain, which can last for days and include muscular paralysis, breathing difficulties, shock and sometimes heart failure or death."
Oceana notes that "the stonefish can inject a venom that is capable of killing an adult person in less than an hour."
But, if you are stung, don't panic.
The U.S. National Library of Medicine notes that you should "soak [the] wound in the hottest water [you] can tolerate for 30 to 90 minutes," and of course call paramedics to further assist you.
You'll know it's a stonefish sting by the "intense pain and swelling at the site of the sting. Swelling can spread to an entire arm or leg within minutes."
Of course, the best method is avoidance. Per the Brisbane Times, "Surf Life Saving Queensland recommends wearing thick-soled shoes and shuffling your feet when walking in the shallows and not pick[ing] up any rocks on the reefs."
So enjoy the water, but keep an eye out in rocky places so that you don't accidentally step on one of these deadly fish.