Tag Archives: sharks

Limiting Factors in Marathon Swimming – Part 2 – Environmental Factors

In Part One I covered the physiological limiting factors in marathon swimming.

The various environmental aspects of a swim are not insignificant. They are especially important in that they all lay outside the swimmer’s control and often even outside the control of the support crew.

Water Temperature


This is generally a known factor prior to a swim. Swims are either cool or cold water like the English and North Channels or warm water swims like Maui, Rottnest, Manhattan or Chloe Maccardels’ upcoming Cuba to Florida attempt. A few fall into an intermediate category defined more by the swimmer’s experience, such as the Catalina and Gibraltar Channels. Sudden changes in temperature are rare in marathon swimming and where they are possible they are also understood; such as South Africa’s west coast which is prone to sudden wide water temperature changes, and the California coast where the sudden transition from very deep water to a shallower continental shelf very close to the  mainland can cause cold water upwelling at the end of a marathon swim. Air temperature is obviously much more variable and a condition of the weather but extremes of air temperature are not usual during a swim. A five degree Celsius differential can be significant for a swimmer if such a drop is also accompanied with a breeze or wind which can sap the swimmer of body heat.


Lion's Mane jellyfish
Lion’s Mane jellyfish

The recent and future attempts at a distance and time records by necessity are held in warmer waters such as Cuba to Florida.  These water are home to jellyfish with debilitating stings such as Box Jellyfish. While the cold waters  of the North and English Channels are home to Lion’s Mane and Portuguese Man O’War’s endurance records are less likely and jellyfish stings in the English Channel are rarely more than intermittent, though the North Channel (the Mouth of Hell) can have miles of Lion’s Mane blooms, part of what makes it the ultimate channel swim. Attempts to swim in these waters divide swimmers in two ways: whether attempts should be made in locations not considered possible without additional protection or exceptions to the usual rules, and if so are jellyfish protection suits acceptable or the thin edge of a wedge that will inevitably lead to more overt (or hidden) performance enhancing suits? (See Evan’s analysis of his survey of marathon swimmers for an excellent overview of the contradictions of divisions and unity in the community).


The Man In The Grey Suit is a subject of great concern (and discussion) for distance swimmers. Not of any real concern here in the north-eastern Atlantic, they are a greater hazard in the warmer waters elsewhere, particularly California, the Caribbean, Hawaii, South Africa and Australia. The Cook Strait Channel swim in New Zealand is unique in having a shark evacuation rule. Shark cages have been used for marathon swims in the Caribbean and South Africa at least. Shark cages are however considered swim assistance as they increase the swimmer’s speed through eddy current drag. Other possible control methods include electronic shark repellents (whose effectiveness is not entirely assured or quantified), armed boat crew or armed or otherwise scuba diver outriders.


These are amongst  the most variable of environmental factors and therefore potentially also the most limiting. Because swimmers move slowly relative to even a sailing boat, we are vulnerable to slight deviations, miscalculations or just insufficient data, the most likely cause. Even in such a well-travelled and mapped location as the English Channel, especially for swimming, pilots will occasionally speak of tides arriving early or late or with a difference force than expected. Tidal currents are understood at a larger scale, hundred of years of navigation have mapped the seas for craft, not for swimmers. Tides act in a similar chaotic way to a weather system, which means that small deviations will always creep in. The only way to improve accuracy of prediction is to improve the data, and this is not practically possible or even desired for small tidal variations. As swims occur in less well-known or new locations, the likelihood of discovering unknown local variations outside marine charts increases. Half a knot current, barely detectable to a boat, is enough to deviate a swim over hours from a projected or necessary course.

Global tides
Global tides

Crew and boat

Any English Channel pilot will confirm that one of the most likely causes of unsuccessful Channel swims is poor selection of support crew. The most likely cause is mal-du-mer, seasickness. For some people seasickness is a completely debilitating ailment that can sap all willpower and strength and there is no way to know whom it will strike. The solution of course is to have experienced crew. Even this can fail because people experienced on powered craft will be at the mercy of the choppy water amplified on an almost stationary craft. Other crew issues can also arise, whether accidents or other illness. Anyone who hasn’t been on a rocking boat looking down on a swimmer is unlikely to understand! And not unknown are mechanical problems on the pilot-boat. Most pilots are by necessity practical mechanics able to address problems as they arise, but not all problems can be fixed with a wrench and hammer while rocking about on the sea.

Channel boat The Viking Princess
Channel boat The Viking Princess out of the water


Weather changes are the bane of English and North Channel swimmers particularly. Other Channels like Tsugaru and Gibraltar and Cook are also subject to constantly variable and unpredictable weather patterns. If you are used to the predictable weather of the west US coast, with morning offshore and afternoon onshore breezes, knowing your swim will almost certainly take place with a 48 window, the difficulty of allocating two weeks or even long (like the North Channel) and still being completely unsure of getting in the water is shocking. Weather constraints obviously ran the full gamut. In the North, English and Gibraltar channels the main concern is wind (and its effect on the seas). Fog can also be a problem with 2012’s Channel season infamously seeing three solos on one day abandoned within a kilometre of France for the first time in 137 years. I’ve warned previously that fog may be the most dangerous weather condition for swimmers. In warmer humid climes like Round Manhattan, and the Caribbean, lightning storms are a serious cause for worry, a swimmer or boat caught exposed out on the water is in real danger. Having to wait for or even postpone a swim is something many marathon swimmers have undergone and the mental pressure this brings is often not inconsiderable, which I will discuss further in the next and final part.

Coming in part three, Psychological Factors.


Man “surfs” Great White Shark

Some headlines are sooo good you have to re-use them, they shouldn’t be touched. From the Guardian.

Doug Niblack

Doug Niblack was trying to catch another wave before going to work when his longboard hit something hard as rock off the Oregon coast and he found himself standing on a thrashing great white shark.

Looking down, he could see a dorsal fin in front of his feet as he stood on what he described as 10 feet (three metres) of back as wide as his surfboard and as black as his wetsuit. A tail thrashed back and forth and the water churned around him.

“It was pretty terrifying just seeing the shape emerge out of nothing and just being under me,” he told the Associated Press on Wednesday. “And the fin coming out of the water. It was just like the movies.”

The several seconds Niblack spent on the back of the great white on Monday off Seaside, Oregon, was a rare encounter, but not unprecedented, according to Ralph Collier, president of the Shark Research Committee in Canoga Park, California, and director of the Global Shark Attack File in Princeton, New Jersey.

He said he had spoken to a woman who was kayaking off Catalina Island, California, in 2008 when a shark slammed her kayak from underneath and sent her flying into the air. She then landed on the back of the shark, Collier said. “At that point the shark started to swim out to sea, so she jumped off its back,” Collier said.

Zach Vojtech of the US coastguard said officials did not officially log shark encounters, but he had learned about Niblack’s ordeal from an off-duty member, Jake Marks, who was nearby when he was knocked from his board.

Marks said he never saw the shark, but saw Niblack suddenly stand up, with water churning around him. He joined Niblack in paddling as fast as he could for shore after seeing a large shape swimming between them just beneath the surface.

“I have no reason to doubt there was a shark out there,” said Marks. “With the damage to his board, the way he was yelling and trembling afterwards – there is no other explanation for that.”

Niblack estimated that he was standing on the shark for no more than three or four seconds. The dorsal fin caught his board and dragged him for about a metre by his ankle tether. “I’m just screaming bloody murder,” he said. “I’m just yelling: ‘Shark!’ I thought for sure I was gone.”

In six years of surfing, Niblack said he had seen sharks in the water, but never so close. He said he had been dreaming about sharks, but was planning to go back out to surf. When he does he will take a waterproof video camera his roommate gave him. He has also put a sticker on the bottom of his board to ward off sharks – a shark with a red circle and a slash over it.

“I’ll definitely go back out,” he said. “It’s just the surf sucks right now. I’ll wait until that gets better, then go back out.”

5 things more likely than a shark attack

Great white shark. Photo by Terry Goss, copyri...
Image via Wikipedia

From The Diving Blog:

  1. Win an Academy Award. Over 50 Oscars are given out each year (including scientific and technical award winners), meaning you are more likely to win the coveted gold statuette this year than get bitten by a shark. Better get crackin’ on that script!
  2. Die while scuba diving. While it sucks to think about, over 100 people die a year while scuba diving, often from unknown causes. You’re more likely to die while scuba diving from something like an equipment malfunction than to get attacked by a shark. There, don’t you feel better?
  3. Dealt a full house—three times in a row. The odds of getting dealt a full house (three of a kind and two of another kind, one of the highest hands in poker) is 1 in 693.Let’s say you spend all night playing poker with the guys. You are more likely to get dealt a full house three times in a row than get bitten by a shark. Just how much money did you win last time you played poker?
  4. Killed by a falling aircraft. In murky waters everyone’s on the lookout for killer sharks. How often are you on the lookout for falling aircraft? Instead of the Great White Shark you should be looking out for the Great White Airbus.
  5. Win a Nobel Prize. Six prizes are awarded. This actually makes your odds of winning any one year lower than getting bit by a shark. However, factor in how often they are awarded, and your odds quickly zoom past shark territory.
Although I prefer the one I read here: you’re 25 times more likely to be bitten by a New Yorker than a shark.

Penny Palfrey and crew CLEARED of shark killing allegations

I’ve been sitting on this news for a few days until it was officially released.

So I’ll start with what Steve reports on Daily News of Open Water. The Investigation reported on Facebook (of all places):

As organizers of Penny Palfrey’s Bridging the Cayman Islands swim, the Flowers Group launched an investigation into the reports and rumors that sharks were killed during this endeavor. 

We have reached out to various Government agencies and members of both the local and international crew.

The findings were that The Cayman Islands Department of Tourism contacted the individual named in the original report, Charles Ebanks, who confirmed that he did not kill any sharks during the historic Bridging swim and states that reports to the contrary are inaccurate. He stated that he “hooked the sharks and lead them away”, he further added, “I was there, I did not kill any sharks. They are assuming I did something which is not true and you can quote me on this.”

Charles stated that the boat captain from the boat asked him what he did with the sharks and he replied, “I got rid of them.” He said he thinks this could have been taken to mean that they were killed.

Based on Charles’ account, various members of the Bridge crew were conferred with, and corroborated this description. Images have also been reviewed from various individuals who were on the boats. From these findings, there is no evidence to suggest that any sharks were killed.

It is unfortunate that these reports caused such a firestorm of controversy. It is hoped that this puts this matter to rest and allows Penny much deserved accolades for this historic achievement.


When I first wrote about this on Monday, I put a non-involved swimmer’s point of view, not attempting to speak for anyone except myself. Not other swimmers. Not conservationists or environmentalists. And I said, also, let’s wait until full story is in. It’s now in.

And in the meantime I saw the story and abuse continue. It’s always easier to throw abuse and get judgemental than wait for facts apparently.

Now my next question: do you think all the people who attacked Penny, Chris, Steve and the crew and swim will now apologise? Yeah, right.

Regardless, Congrats again to Penny, Chris and Steve and crew.

Penny Palfrey

Any chance the rest of the critics would like to go back to doing something productive about the 70 million sharks killed every year? And maybe leave us real sea people to our selves and the sea?

It’s actions like the attack on Penny and crew that stop me from describing myself as an environmentalist a lot of the time.

Updates continue on the Penny Palfrey story.

If you were interested in the Penny Palfrey story yesterday, then it is important you continue to follow it. I said yesterday I had seen a lot of vitriol thrown online at Penny and crew and I said we needed to wait for the full story. Apparently even that was unacceptable for some, it’s always easier to accuse and judge than to listen.

Alleged shark killing during Penny Palfrey’s Cayman Islands swim

White shark
Image by Ken Bondy via Flickr

EDIT: updated.

EDIT 2: See the results of the investigation here.

This may be the biggest subject in OW swimming this week.

Here’s a long story about killing of endangered (Oceanic White Tip) sharks during Penny’s swim. Here’s the follow-up with comments from Penny’s husband. Here’s Steve Munatones article on it.

I recommend reading the comments on all also to see some of the bile directed at Penny and crew and some different opinions. If my very limited experience of press is anything to go by, the truth will more complex than is currently being portrayed.

Some comments I would make as a swimmer:

  • There has to be complete trust between a swimmer and crew. The swimmer rarely knows the full story from the crew. Some swimmers want to be told the truth, some want to be lied to. Only distance swimmers and crew will really understand this dynamic. Afterwards or even during you might be angry or disagree with even simple things happening. But as a swimmer you’ve put your life into the hands of the crew. Make no mistake, distance swimming is one of the most extreme sports and it takes more than just the swimmer to accomplish.
  • I haven’t met Penny Palfrey (though we have people we know in common). I’m pretty certain that she feels as I do about the sea, that she loves it and all its glory in the way only someone who spends their life in it could. I sure she is upset at any loss, more so than people that have never swum a metre or spent time in the sea and even more upset at the coverage and the vitriol aimed at her swim, but I doubt she feels she should have sacrificed herself. I’ll be interested in her thoughts. IF the events happened as are being  portrayed, it’s entirely possible  that she wishes she’d been pulled but she would not have been aware of anything. The swimmer is both the boss and the least aware, at the same time, but never in charge. That apparent dichotomy exists in every swim. But it’s also possible that she is happy with the situation as I’m sure she knows more about it than we do. I’m not a mind-reader and can only speculate.
  • Any possible legal proceedings should it be determined there is a reason, would be interesting. Since I swim in water that doesn’t have fish (only dangerous sharks are called fish by OW swimmers), I don’t know whether they had to get any different permits for this swim. Or, if it happened outside territorial waters, then there will be no proceedings since as far as I am aware it’s not a protected area. Don’t misunderstand me there, I’m not saying something is ok or not depending on where it happens.
  • The bile and hysteria toward Penny is completely unwarranted. People who wring their hands dump plastic that kill birds and turtles. They flush their condoms to choke wildlife. They eat fish that are only caught by processes whose byproduct is the seas being emptied (e.g. shark bycatch). They throw and flush their shit and phosphates everywhere and dump their poisons in the sea and still lecture other people while they drive around in SUVs. Environmental improvements will never be achieved by screeching mobs or dictats but by consensus amongst everyone. This is actually one of the primary tenets of the environmental movement but unheeded both by Green politicians and many activists. (The sea led directly to me doing an environmental Master’s degree. The article I’d actually already written for today was about wildlife loss in the Atlantic).
  • “Fish skin is used as a source of gelatine as well as leather in making clothing, shoes, handbags, wallets, belts and other items. Larger fish are more suited to leather production owing to the size of the skins. Common sources of leather include shark [...]. Shark cartilage is used in many pharmaceutical preparations and reduced in powder, creams and capsules, as are other parts of sharks, e.g. ovaries, brain, skin and stomach … Several splits by more product forms for several species have also been introduced, in particular for meat and fillets, as well as the introduction of shark fins in cured form.[...] UN – State of World Fisheries 2010.
  • Some 73 million sharks are killed by man every year, mainly for their fins. That averages out to well over six million per month, more than one and a half million per week, over 217,000 per day, upwards of 9,000 per hour, and around 150 per minute. In fact, in the 40 hours and 41 minutes it took Palfrey to break the world record for longest unassisted oceanic swim, over 366,000 sharks were killed somewhere in the world. – From the link above.
  • If I was in a situation where something the choice was between a swim and an endangered animal, I’d prefer to have my swim abandoned that have that endangered creature killed for my swim. But if a crew told me they killed a shark for my safety, I’d ABSOLUTELY believe and trust them. Those two things are completely compatible.
  • The fundamental question being asked by many is whether any swim is worth such a price. For this particular swim, I think we still need more clarity, and certainly not a rush to judgement.
  • I ask you this: if such swim are to be abandoned, then why is all the other mass- scale killing allowed? Personally, I have long been in favour of Marine Protection Zones (Reservations) rather than just a quota system. Quota systems, which are the primary method of marine protection are open to widespread corruption and lobbying and local political pressure. And they generally don’t work. The world has very few Marine Reservations. Marine biologists and environmentalists believe Marine Reservations (and outright bans) are the best way to protect species and habitats. If the Caymans were a protection zone or marine reservation, with NO marine traffic, then such swims should be abandoned. But let’s see how many will stand up for that. What, why we can’t go there? But how many creature are killed unknowing by propellers and dumped rubbish from boats and pollution? It’s hypocrisy to attack the swimmer and crew in ignorance while the rest of the world does its best to destroy everything.
  • I consider myself an aquatic creature. I have as much right to swim as any other creature. Being a thinking creature also, I seek for balance and understanding and an awareness of the world around me. I constantly fail.
  •  I’m also an environmentalist. But environmentalism has to exist in a real, contested world.
Disclaimer: The second article above seems to me to imply Steve Munatones is lying (I’d be very unhappy about it if I was Steve). I don’t believe this. Steve was there, unlike the others. If Steve says it didn’t happen, I believe him, it didn’t happen. Steve is the foremost promoter of Open Water swimming in the world, and is always open in his opinions. I know Steve from personal email discussions, he reads here occasionally, and he has featured my writing and interviewed me for Daily News of Open Water. (And Steve and I have disagreed in the past also, and no-one who knows me would accuse me of sycophancy).