Scuba Diving's Urban legends debunked
Updated: Aug 6, 2019
How did the diver in full gear end up dead in a forest? He got scooped up by a helicopter collecting water to put out a forest fire and fell to his death when the water was dumped. One of the many urban legends that has got around over the years about scuba diving. Since everyone likes a good story, we thought we would compile some of the weirdest, truest and funniest legends we’ve heard in the last few years. We hope you’ll join in to share some of yours after reading this post.
# Menstrual blood attracts sharks
Female instructors could look forward to big tips on those days then since most divers want to see sharks but alas it is but an urban myth. The quantity of blood seeping into the water is very small even for a shark to detect. Sharks only really detect one part of blood in 100 parts of water. A small graze in the water would probably release more blood. What’s more, sharks are not interested in blood per se but in the amino acids contained in the blood that can lead them to their favourite foods, which is not human flesh, despite what Hollywood would have you believe.
# Sharks never sleep
This is a tricky one for several reasons. Firstly, there are a lot of different sharks out there with a lot of different behaviours. However, it is true that some species cannot stop swimming because they need to have water constantly moving over their gills so they can breathe, so they can’t lie on the bottom and rest like some of their counterparts. If you look at the oxford dictionary definition of sleep : ‘A condition of body and mind which typically recurs for several hours every night, in which the nervous system is inactive, the eyes closed, the postural muscles relaxed, and consciousness practically suspended’; then sharks don’t really sleep. They don’t have suspended consciousness; they don’t curl up and switch off every night. Nevertheless, sharks do get rest, they sleep swim and continue moving in a trance like state. So whether sharks sleep really depends on what you define as sleep, if it’s resting your mind and recuperating then yes, if it’s curling up in a duvet and switching off for 8 hours the answer is clearly no, they never sleep!
# The sea snake’s mouth is too small to bite you
You won’t get bitten by a sea snake because its mouth is too small unless it gets you between the fingers or on the ears. Just swim around with your fingers tightly stuck together and your hands over your ears! This one is complete legend but so funny. Sea snakes like all snakes have an additional bone in their jaw which allows them to swallow preys much bigger than their head. They can open their mouth very wide and could bite you if they felt like it. But they don’t. Well, not often, anyway. A man was killed from a sea snake bite in Australia in 2018, he is believed to be the first in 80 years. I think we’re pretty safe.
# Moray eels are aggressive and snap at divers
Moray eels have a bad reputation. Even seasoned divers often think of them of evil and aggressive. ‘The Little Mermaid’ didn’t help their case with them being portrayed as the evil sidekicks of the baddy (Ursula, the octopus witch, in case you don’t remember). They do seem pretty scary, rudely snapping their big mouths at you as you swim by; but they are victims of a real personality smear. The poor morays have to open and close their mouths constantly in order to breathe. Most fish have gill covers that pump water through the gills, Moray eels don’t have these, so they have to open and close their mouths to pump the water through and breathe. This gives them a slightly threatening look. What’s more they have very poor eyesight and some silly divers think it’s fun to feed them or stick their hands into a moray’s lair. Those fingers could be food or a predator to the moray who sees little and doesn’t recognise the alien smell and when in doubt, the best way to find out is to, well, take a bite… But they’re big softies really.
# There’s a rubbish patch the size of France in the Pacific Ocean
This is sadly true. In fact, it’s 3 times the size of France and is in fact one of 5 big ocean gyres collecting the rubbish we dump in our seas daily. Annual consumption of plastic is 320 million tones and is on the rise, mindbogglingly. Several initiatives like The Ocean Cleanup are finding ways to clean some of it up but what really counts is not increasing it. The legend that we could live with much less or no plastic at all may be true after all, if we all make an effort. Help clean your beaches and reduce your plastic consumption as much as you can.
# Urine dissolves sea urchin spines under your skin
On a lighter note, this one is clearly a fib invented by people who enjoy peeing on other people. However, Ondinists, (the official name for the afore mentioned people) can rejoice since they can pee on people who’ve suffered from a jelly fish sting. It’ll actually help if you don't have vinegar to hand (a bit: they’re both acids, acetic and uric).
There, our collection of diving’s best-known urban legends has come to an end. However, we would love it if you could send us some more. Send your legends on our Facebook page and we’ll publish the best ones!