Special Great White Shark Expedition

Shark Diver is excited to announce that we will have a very special expedition to Guadalupe Island this fall. From Sept. 8-13 we will have both Nicole Nasby-Lucas, the scientist responsible for the Guadalupe Photo ID database and Tanya Houppermans, a world-renowned underwater photographer on board. Nicole has been studying the white sharks of Guadalupe Island, Mexico since 2001. Her research includes satellite tagging and tracking studies to examine migration patterns and behavior. She also…

Is shark diving good for conservation?

Conservation and Shark Diving are often seen as opposites and not compatible. Let’s look at some of the concerns raised and see how valid they are. The biggest issue a lot of people have with shark diving and specifically feeding dives is that “It conditions sharks to associate people and divers with food!” While it does indeed condition sharks to associate divers with food, it definitely doesn’t condition those sharks to associate divers AS food….

Guadalupe Great White Sharks in danger.

I started SCUBA diving and spear-fishing at Guadalupe Island in 1996, 5 years before we started shark diving there. It is during that time that we discovered the Great White Sharks that are aggregating at there. At first it was just the occasional encounter, mainly while spear-fishing, but over the years those encounters grew in frequency and it was not unheard of to see a GWS while SCUBA diving.  My first encounter with a GWS happened…

Why do sharks attack?


Why do sharks attack?

Recently there was another shark attack on a spear fisherman in California and a fatal shark bite at Cocos Island in Costa Rica.  Inevitably when someone gets bitten by a shark, there is speculation about why it happened. “Mistaken identity” is a popular explanation, and of course the people arguing “it’s their home” and the “fill in the blank” kills more people than sharks every year are always ready to chime in.

There are statistics on shark bites, like the “international shark attack files” by the Florida Museum of Natural History, and we have a pretty good idea of how many people actually get bitten by sharks each year. Most of those statistics only collect data on what happened and are recording the circumstances of the attack. Since in very few cases was the shark actually seen before it bit the victim, most of the information we have is only about what the victims were doing before they got bit. When we discount the provoked attacks, like someone pulling a nurse shark by the tail, a fisherman getting bit by a shark he hooked, or like in the case of the Manhattan Beach incident, a fishermen hooking a shark and pulling it through a group of swimmers, very little is known about what the sharks were doing prior to biting the victim.

Obviously I don’t know what those sharks were doing or thinking either, nor do I know what lead them to bite. I wasn’t there and don’t have any firsthand knowledge. What I do have is some first hand knowledge of how some of the shark species implicated in attacks on humans behave and how that behavior might determine why they attack.

I have been diving with and observing Great White Sharks for over 17 years at Guadalupe Island and been around Bull-, Tiger– and Hammerhead Sharks for more than 6. What I found is that there are a lot of misconceptions about how these animals behave. Probably the biggest mistake is that people think “A shark is a shark”, pretty much assuming they all behave the same way.

There are well over 400 species of sharks, with most of them absolutely harmless to humans. Think about it this way. We have the top 10 deadliest sharks list. With an average of fewer than 10 fatal shark bites worldwide each year, that means that if a species is listed as #10, it stands to reason that that species is responsible for fewer deaths than #1, it may in fact only be responsible for a death every 30-40 years. Most of the species responsible for deadly bites on humans are the Great White, Tiger and the Bull Shark.

So let’s take a look at a couple of those species.

Great White Shark

The Great White Shark is probably the most feared animal in the world. Movies like “Jaws” and the way the media reports any encounter with them have instilled fear into most people who contemplate going into the Ocean. The thinking that one drop of blood in the water will cause a huge frenzy and pretty much any shark within 10 miles will come and attack you is very common.

The reality looks a lot different. Did you know that Great White Sharks don’t “frenzy”. In 17 years of observing them, I have never seen a bunch of Great Whites buzzing around a food source or a prey animal. When we put tuna heads in the water, or back when we used chum to attract sharks, we sometimes have to wait for hours for a shark to approach the cages. We could see them swimming below, but even though there was fish blood and Tuna in the water, they would not come up. When multiple sharks are around a food source, they typically measure each other up in order to decide who gets first crack at the food, instead of a free for all frenzy.

If that measuring doesn’t settle it, the bigger shark tends to bite the smaller one to assert it’s dominance. It is only after the pecking order is established, that they go after the food. They give each other space, with the smaller ones only going for the food after the bigger shark is a safe distance away.

Another common belief is that Great White Sharks will attack just about anything, even if they don’t know what it is. My observations have actually shown that Great White Sharks are not only very cautious, but seem to be almost timid. For example, a couple of years ago, a beach towel fell overboard and 3 sharks came to investigate it. 2 of them jerked away and took off, like something was chasing them, while the 3rd shark kept approaching it, jerking away repeatedly, until I lost sight of both the towel and the shark. I don’t know if the shark eventually bit the towel to figure out what it was, but it clearly kept checking it out repeatedly, being very cautious in it’s approach. We have actually observed the same timidness in some sharks when they approached a Tuna head. They clearly smelled the tuna, but when it was pulled slightly when they approached, a lot of them jerked away and would not attempt to bite the tuna until the made several passes to inspect it.

Screaming Mimi, a subadult female Great White Shark swam by my go pro that I had on a 20ft. pole 3 times, coming really close and checking it out, before biting it on the 4th pass. Again, she didn’t just attack, she first checked out the go pro a few times, before she decided to take a bite at it.

Another interesting observation we made is that Great Whites attack a sea lion differently than a seal. If they are not biting their head off, the bite a seal in the butt, because seals swim with their  rear fins, while they bite sea lions in the pectoral fins, which is the way they swim. So if Great Whites know the difference between a seal and a sea lion, I think it’s unlikely they would mistake a surfer for a turtle or a sea lion.

There is a general belief that if you are bleeding, a shark can smell your blood from miles away and will come and bite you. Did you know that the Great White Sharks can differentiate between the blood from different species of fish? There is a distinct difference in how they react when they smell tuna blood, vs. yellow tail blood. So if they can tell the difference between the blood from different fish, it stands to reason that they can tell the difference between human blood and the blood of a seal or fish. Instead of increasing the chance of an attack, I actually think that if you are bleeding you might be even safer. Since your blood is giving the shark a way to know what you are, it actually might prevent an investigatory bite.

So why do White Sharks attack? There are of course different reasons. In the case of the spear fishermen who got bit in California, I believe that the shark wanted the fish and is was not actually going for the diver. When we were spear fishing at Guadalupe Island, we always put the fish on our float and didn’t attach it to our body, so that if a shark wanted the fish, it would not come for us. With surfers and swimmers, since I don’t believe in the mistaken identity, I think that most bites were actually an investigation. After they checked out the victim for a while, they took a bite, trying to figure out what it is.

However, I don’t want to take away the possibility that some of the bites are actual predatory attacks. Bites on humans by Great White Sharks are extremely rare, and the number of actual predatory attacks even rarer. While Great Whites are not mindless killers, out to get us, they are apex predators and definitely not harmless pets. There is no need to fear these animals, but we have to respect them for what they are.

Bull Sharks

We all heard that Bull Sharks are the most aggressive, because they have more testosterone than any other shark. While the testosterone part may be true, it has nothing to do with them supposedly being aggressive. People mistake aggression with hunger. When a Bull Shark is hungry, it has to eat. Unless it finds some animal that is already dead, that means it has to hunt and kill something. That’s not aggression, that’s just simply feeding. Aggression is fighting for territory, dominance etc. and that is actually something that is strangely absent from my observations. In an environment, where up to 70 bull sharks were competing for food, I’ve seen multiple sharks go for a tuna head, without any of them biting the others to get to the food. It was very rare to see a Bull Shark with a bite mark on them, something that definitely can’t be said about White Sharks.

Something I found out in Fiji really surprised me. DaShark, told me that the Bull Sharks that are taking tuna heads offered by hand from a feeder, are not the same as the ones who go for the tuna heads dropped from a trash can. He even told me that sharks that take a tuna head from one particular feeder would not take it from a different feeder. I would have thought that as soon as the sharks smell and see the tuna, they would go for it and not be picky.

Bull Sharks don’t naturally hunt for prey that is human sized, but they do hunt in brackish water, where the visibility can be quite bad. That is also the place where a lot of humans are in the ocean. So I think it’s not the “fact” that they are aggressive and attack anything, but rather their proximity to humans that makes it more likely that they are implicated in an attack. When chasing fish, Bull Sharks are not stalking. They pretty much have to attack at full speed in order to get the fish. When they are hunting, specially around humans, it’s easily possible that a foot flashes in the middle of some fish and the shark bites it by mistake. Also while more common than bites by Great Whites, Bull Shark bites tend to be less severe.

So what does all this mean for anyone going into the ocean? First and foremost, think about the rarity of a shark bite. There are far greater dangers in the oceans than sharks. Currents, waves and heat strokes have killed more people in the ocean than sharks. You are also more likely to get hurt on the way to the Ocean, than by a shark in it. There are however some common sense things you can do though to reduce the extremely small chance of getting bit even further.

1. If you see a potentially dangerous shark, get out of the water while keeping your eyes on it. Since they are stalkers, they are unlikely to attack when they first notice you and since they like to ambush their prey, they are less likely to attack if they know that you see them.

2. Don’t swim at dusk and dawn, when sharks tend to be more active.

3. Avoid shiny jewelry, sharks hunting in shallow water might mistake that for a fish.

4. Don’t go spearfishing or surfing in an area known to have big predatory sharks. In some areas that depends on the time of year.

Again, to put everything into perspective. In California, some of the most famous surf spots are in an area that seasonally has adult White Sharks. The busiest time for surfing is before and after work, dusk and dawn, the time sharks are most likely to hunt. The surfers are on the surface of the water, the most dangerous place in the water, because these sharks tend to attack from below, yet with all that, in 100 years from 1900 to 2000, there were only about a dozen fatal shark attacks. That’s about one every 9 years and those happened all over California, not just the area where White Sharks aggregate.

Bull Sharks can not only swim in salt water, but can go from salt to brackish and even fresh water. That fact means that they tend to be in waters that are also frequented by humans, which naturally increases the chances of that species being implicated in an attack. With the ever growing number of people going into the water, we would expect the frequency of bites to go up every year, something that actually hasn’t happened.

When it comes to our fear of shark, I keep thinking of a quote by President Roosevelt that says: “the only thing we have to fear is…fear itself”.

Go out and enjoy the Ocean. And if you want to observe these awesome animals yourself, let’s go shark diving!

Martin Graf
CEO Shark Diver

About Shark Diver. As a global leader in commercial shark diving and conservation initiatives Shark Diver has spent the past decade engaged for sharks around the world. Our blog highlights all aspects of both of these dynamic and shifting worlds. You can reach us directly at crew@sharkdiver.com.

What’s eating the brains of sharks and rays in California?

Between February and July, there have been a lot of incidents, where dying or dead sharks and rays have washed up on beaches in San Francisco bay. What is causing them to die?

According to an article in National Geographic, CDFW senior fish pathologist Mark Okihiro, Joseph Derisi, an expert on the genetics of infectious diseases at the University of California, San Francisco and Hanna Retallack, an MD-PhD graduate student have found the answer.

Their headline reads : “Mysterious Brain-Eating Shark Killer Identified, Though Questions Remain”

It looks like the culprit is “a well-known fish-killing parasite called Miamiensis avidus.”

The article further states: This appears to be the first case, Retallack said, of Miamiensis avidus infecting wild sharks. It’s noteworthy, she added, because sharks are evolutionarily quite different from the bony fish that have previously been known to suffer infections. 

Read the entire article here

Martin Graf
CEO Shark Diver

About Shark Diver. As a global leader in commercial shark diving and conservation initiatives Shark Diver has spent the past decade engaged for sharks around the world. Our blog highlights all aspects of both of these dynamic and shifting worlds. You can reach us directly at staff@sharkdiver.com.

What causes sharks to have crooked spines?

Earthtouchnews has an article describing a bull shark with a crooked spine. That shark was found by the shark lab in Bimini. They named him “Quasimido” and are speculating on what caused that deformity.

The Bimini Shark Lab team secures “Quasimodo” for workup (a short checkup that includes taking various measurements of the animal). Image: Chelle Blais/Bimini Biological Field Station

Sarah Keartes writes: “Dr. Natalie D. Mylniczenko, a veterinarian who has spent time with the Shark Lab beforepresented several possible explanations for the bull shark’s strange skeleton. It’s possible that a deep abscess, granuloma, or slow-growing cancer is to blame – but Quasimodo’s overall state seems to suggest otherwise. If disease were at the root of the deformity, we would expect to see at least some abnormal behaviour. The more likely culprit, according to Mylniczenko, is either a congenital or traumatic incident. In either case, this would have occurred when the shark was very young, and over time, his body would have compensated and healed in a skewed position.”

Read the full story here: https://www.earthtouchnews.com/oceans/sharks/meet-quasimodo-the-bull-shark-with-a-very-crooked-spine/

Image: Chelle Blais/Bimini Biological Field Station

This Bull Shark is not the only shark with a deformed spine. At Guadalupe Island, we have our own Great White Shark with the same deformation. When we first met her a couple of years ago, I nicknamed her “Kinky” because of the very distinct kink in her tail. I have no idea what caused that kink, since she doesn’t have any obvious scars or signs of injury. She was named “Screaming Mimi” by someone through the “Sponsor a shark” program of the Marine Conservation Science Institute. That sponsor program, is one of the ways they raise funds for the Photo ID database at Guadalupe Island.

“Screaming Mimi”

Just like the “Quasimodo” in Bimini who was seen swimming around a couple of weeks after the people from the Shark Lab examined it, “Screaming Mimi” also seems to be doing well and has been very active around our cages at Guadalupe Island.

If you want to meet “Screaming Mimi”, or any of our other sharks at Guadalupe, contact us at 619.887.4275, crew@sharkdiver.com or www.sharkdiver.com

Let’s go shark diving!

Martin Graf
CEO Shark Diver
About Shark Diver. As a global leader in commercial shark diving and conservation initiatives Shark Diver has spent the past decade engaged for sharks around the world. Our blog highlights all aspects of both of these dynamic and shifting worlds. You can reach us directly at staff@sharkdiver.com.

Deadly tiger shark stalks stranded diver?


The sensationalist media is at it again, or should I say still at it? This time it’s an outlet not normally prone to sensational headlines. Sky News has a headline that reads Deadly tiger shark stalks stranded diver four miles back to shore”

Tiger Shark

Turns out that a spearfisherman got separated from his boat and had to swim back 4 miles to shore. What they describe as A diver who became separated from his boat has said he is lucky to be alive after swimming miles back to shore while being stalked by a large tiger shark.” and “He swam…in shark-infested waters. I just can’t believe anybody could do that. It’s such a massive effort.”, was in reality just a really long swim, where he encountered a couple of sharks.
That “deadly” shark was just checking him out and the diver even says that “For about 500 metres the shark swam on the same path as me towards the shore and then in a moment banked and disappeared completely as if to say ‘you’re OK now, I’ll leave you alone’. So the real danger to the diver were not the sharks, but the fact that he had to swim for 4 miles to reach shore.

Tiger Shark coming close to a diver

Maybe a headline that says “Diver lost at sea has to swim 4 miles to reach shore” or something similar would be more appropriate than making the sharks out to be those mindless killers again, would be more appropriate.

Me with a Tiger Shark ©Rene Buob

We dive with Tiger Sharks in various places around the world and learned that we have to respect them, but there is no need to fear them. They are neither mindless killers, nor harmless pets, but awesome predators that are curious, but in most cases not interested in attacking us.
Martin Graf
CEO Shark Diver

About Shark Diver. As a global leader in commercial shark diving and conservation initiatives Shark Diver has spent the past decade engaged for sharks around the world. Our blog highlights all aspects of both of these dynamic and shifting worlds. You can reach us directly at crew@sharkdiver.com.

Six new sharks at Guadalupe Island

This season has started out completely different from the last. Where we had lots of juvenile females early last year, this season it has been all males so far. On our last expedition, we saw 30 different Great White Sharks, with 6 of them being first timers.

The Marine Conservation Science Institute marinecsi.org is keeping the photo ID database and you can contact them if you are interested in naming one of these sharks. I don’t want to keep referring to them as “Unknown 1” etc. Naming a shark is a great way to support the research and how cool would it be if you see “your” shark on sharkweek?

The only female we have seen so far this season is “Screaming Mimi”. She is as active and curious as she was last year and has given our divers many memorable moments.

Aside from all the new sharks, we have also been visited by a lot of our regulars. Bruce, Bite Face, Chugey, Andy, Hunter, Silent Hunter Bolton, Ace, El Diablo, Johnny, Jacques, Mickey, Sad Face, ChumChum, Thor, Atlantis, Drogin, Joker, Monkey, Hooper, Horizon along with a few that are as of now unnamed, have all made an appearance. We had 30 different individuals on our last expedition!

Here are a few of our new sharks.

To sponsor one of these beauties, contact MCSI here.

To join us on one of our expeditions, contact crew@sharkdiver.com or call 619.887.4275

Let’s go shark diving!

Martin Graf
CEO Shark Diver

About Shark Diver. As a global leader in commercial shark diving and conservation initiatives Shark Diver has spent the past decade engaged for sharks around the world. Our blog highlights all aspects of both of these dynamic and shifting worlds. You can reach us directly at staff@sharkdiver.com.

Which sharks are back at Guadalupe Island?

We just came back from our first expedition of the year to Guadalupe Island, where we saw 12 different sharks. As is usual for this time of the year, the smaller males were the most frequent visitors to our cages. On our trip we saw the following sharks that are all in our photo ID database.

#107 Atlantis: He was the first shark that showed up on day one and stayed around all day.

#65 Johnny: He came really close to show off his new mutilation to his tail. He’s now sporting a cut in the center of his caudal fin.

#206 Poseidon: He was super active and made may close passes by the cage.

#97 Drogin: Drogin was his usual self. He’s a super active shark, coming at the cages from all different directions, trying to steal a hang bait.

#188: We can’t leave this shark without a name! How would you like to name him? Contact http://www.marinecsi.org/ and sponsor his name! Make it a cool one! He deserves it!

#149 Kenrick: He was one of the bigger males that showed up and swam around like he’s the boss. He’s still a sub-adult though and won’t be the dominant one, once Bruce, Bite Face, Thor etc. show up.

#168 Sad Face: He was named last year, because he had bite marks that looked like a sad face on his side. This year those marks were barely noticeable, so it’s a good thing that we can use the color markings to positively identify him.

#121 Don Julian: He’s growing up. Last time I saw him, he was probably close to a foot shorter than he is now. Maybe in a couple of years he’ll be mature.

#199 Who wants to name this awesome shark? Contact the Marine Conservation Science Institute to sponsor his name.

#186 He came by with a bunch of pilot fish. He can also be named by contacting http://www.marinecsi.org/

#83 Joker He was pretty shy and didn’t come close.

We also saw a young male with a cookie cutter bite on his head, but I didn’t get any photos of him, so I couldn’t identify him.

Tonight we leave for another trip. I can’t wait to see who else is back at Guadalupe and am ready to meet some new sharks. Last year we added 29 new sharks to our database, how many will it be this year?

Come join us and get to know these awesome creatures. How great would it be to know the individual shark, next time you watch shark week? Call 619.887.4275 or email crew@sharkdiver.com for more information on how to join.

Let’s go shark diving!

Martin Graf
CEO Shark Diver

About Shark Diver. As a global leader in commercial shark diving and conservation initiatives Shark Diver has spent the past decade engaged for sharks around the world. Our blog highlights all aspects of both of these dynamic and shifting worlds. You can reach us directly at staff@sharkdiver.com.

47 meters down, review by Cindy Michaels


Shark Diver’s Communications Director, Cindy Michaels is not just the heart and soul of our company, she’s also a former writer, broadcaster, news director and professional movie reviewer.
Her review of 47 Meters Down combines her experience from her previous work, with the knowledge she has about the subject matter of the movie, Shark Diving.

Enjoy her review!


By Cindy Michaels,

Before I begin my informative rant about the movie 47 Meters Down, keep in mind that the film was originally only meant for a 2016 DVD release under the name In the Deep. (My grandmother always said, “leave well enough alone.” Apparently, they didn’t listen to my g-ma.) A film company bought the rights, recalled the DVDs, and it was unfortunately released on the big screen. But some DVD copies that had already been distributed to retailers landed in the hands of the public. So if it becomes a cult classic, those DVD holders may be able to make an extra buck for owning a collector’s item. My suggestion… recycle at your local redemption center.

The movie: I laughed; and frustratingly so. Mandy ‘Moan’ Moore stars in this unrealistic film about two sisters that venture to Mexico for a little R and R. The girls get sweet-talked by a couple of local guys into taking a shark dive in a surface cage. Now, I would normally say…”good move, guys!” But the boat was rusty, rickety, and run by a scruffy Captain Taylor, played by Matthew Modine. Ohhhh Matt.

Anyway, things go horribly wrong and the cage drops 47 meters down. Yada yada yada. That’s 154 feet! Have any of you dived that far down? If so, you know your dive time changes dramatically; air is used 4.7 times faster at that level. But for Kate and Lisa, or rather the writers of this mess, no rules apply. The girls are having conversation, hugging each other, and yes, Mandy Moore cannot stop moaning. They just would not have had the time to do all that. One intake from all her crying would have used up the air she had left. And for the amount of times each of them tried to swim to the surface but were told to go back down to the cage…seriously? If you’ve already gone half way, keep swimming! Just keep swimming. Just keep swimming.

I ponder this one. Why did all the guys that took them on this venture hang around topside with spear guns, waiting for the girls to be rescued by the Coast Guard? If Kate and Lisa make it to the top, there’s NO WAY the boys are getting another date! “Hello, Mr. Coast Guard man, what’s your name?” And where are the big beautiful great whites? There really weren’t that many in this film. Clearly Bruce or Lucy would have said ‘hello.’ They must have found more entertaining places to swim, like Guadalupe Island, chatting it up with our divers!

Ok, for those of you (and there’s got to be at least 1) who are a tad bit apprehensive about cage diving, after nervously sitting through 47 Meters Down, let me reassure you of some vital things.
Our cages are awesome! They are reinforced with floatation material bolted to the INSIDE and indestructible, water-tight dock floats secured to the outside; four on each cage. The cages are tied together and then attached to the boat at 3 points by chains and lines.

our surface cages are attacked to the vessel

My friend, the cages are secure; they are basically an extension of the boat.
And just for giggles, I’ll tell you this. If our crew was in that movie, they would have jumped overboard to save Kate and Lisa with their bare hands, strong arm muscles, and fearless attitudes! All would be safely brought on board OUR VESSEL, just in time for a lovely sit-down dinner specially prepared by our fabulous chefs, Mark and Shay.

So, please don’t let Mandy Moore moan you into being afraid of cage diving with us. It is an incredible experience where we INVITE shark folk, like Bruce, Lucy, Chugey, Scarboard and the rest of our fishy friends, to come say ‘hi.’ If they were willing, we’d invite them to dinner. Mark! Prepare the tuna!

~Shark Diver has been diving with great white sharks for 16 years with a 100% safety record. Our great white shark diving season at Isla Guadalupe, Mexico runs from August-November. We take 18 divers per trip and treat our guests to 3 meals a day, unlimited snacks, beer and wine, a comfy bed and fluffy pillow, and lots of excitement. Dive equipment provided, no certification necessary, shark-sighting guaranteed. We love the sharks and you will too. Come dive with us! www.SharkDiver.com

Let’s go Shark Diving!

About Shark Diver. As a global leader in commercial shark diving and conservation initiatives Shark Diver has spent the past decade engaged for sharks around the world. Our blog highlights all aspects of both of these dynamic and shifting worlds. You can reach us directly at staff@sharkdiver.com.