How Great Whites Attack Their Prey
by Lawrence Groth
What is an ambush predator?
Ambush predators – also called sit-and-wait predators – use stealth and camouflage to hide from their prey until quickly attacking by surprise. The great white shark is one of the most remarkable ambush predators on the planet!
What do great white sharks eat?
How does a great white shark attack?
Can great white sharks fly?
How many seals does a great white eat?
Advice for Your Upcoming Excursion
by Christina Owens
Read and Review All Paperwork
You should always know what you're signing! Whether it’s the deposit form for your adventure or the refund policies, take time to read through the forms. Always call if you have a question about paperwork. Also, keep a copy of your paperwork on file.
Check your passport!
Make sure it’s valid for the dates of your trip. Most United States passports for adults are valid for ten years. Children under 16 are usually issued five-year passports. Many countries will require your passport to be valid for at least six more months from the date you arrive. To learn how to apply for a passport, click here.
Make a List and Check It Twice
The open ocean isn’t the place to realize you've left something behind - especially for critically important items such as medications, camera equipment, contacts/eyeglasses, and your passport. Envision your day and then walk through it, making certain you have the things you need and aren’t wasting space with things you don’t. (Click here for sample travel lists.)
Space is often at a premium on a dive trip. Keeping your gear organized in a gear bag throughout the trip is one of the best things guests can do to help things run smoothly. For Guadalupe, remember that the weather can vary from mid-70’s during the day to mid-50’s at night, so pack comfortable, practical layers. Click here for sample packing lists.
Start Your Seasickness Meds Early
Every time someone tells me “I never get seasick,” I cringe. While it may be true for some people, it's also the mantra which was recited by many guests who later found themselves getting sick at the sight of a mere dinner roll. Since most seasickness medications are only effective if you start them prior to becoming ill, start taking them at least 12 hours prior to boarding the boat. Our recommendations are Bonine, Scolpamine (seasickness patches) and Zofran (nausea), however, you should see your doctor for medical advice. Click here for more information on seasickness solutions.
Take Cash for Incidentals and Crew Tip
You may want to purchase souvenirs on the boat at the end of your trip. Hats, t-shirts, sweatshirts and other clothing are often available, and can range from $18 to $80. Regarding tips, an industry standard for a crew working hard to make you comfortable is usually 10% of the cost of your trip. Another reason to have cash handy is for alcohol, beer, and wine. (While alcohol is included in the price of many trips, some of the boats do charge for it. Check your trip information to verify.)
Bring a Garbage Bag or Large Ziplock
Although bags to transport your wet items are often available on the boat, it’s just easier if you have the right-sized bag tucked away in your luggage. That way, when you’re ready to pack you simply have to put your wet stuff in the wet bag, throw everything else in, and you’re good to go.
Be in the Moment
You've wanted to dive with great white sharks for a long time. So don't forget to put down your cell phone or camera and take time to appreciate where you are and what you're doing. And if it’s not sharky at that very moment, take a look around and appreciate everything else the ocean has to offer. You’re doing something others only dream about. Make your time at Isla Guadalupe or the Farallons count!
Don’t Be Afraid to Ask Questions
Shark cage diving is a unique experience, and it generates many questions. Some may seem major, like "Is shark diving safe?" Others may feel trivial, such as "Should I take my own snacks?" But trust me - if you’re thinking it, you should ask it! We want you to feel confident and educated and will spend as much time as you want talking sharks. (And no, you don’t need to take snacks. Plenty will be provided for you.)
Shark Photography 101
by Nikki Sevy
Advice for the brand-new or novice cage diving photographer
There are lots of books and internet resources about photography for scuba divers. But great white shark cage diving is a unique situation. This is the first of several articles we'll be providing to help you get the most out of your cage diving expedition photos!
1) Research the Location
Learn as much as you can about the location where you will be diving. Know the typical water and photography conditions. The best way to do this is asking people who have already been there. Let's talk!
2) Know How to Use Your Camera
Don't wait until you get in the cage to figure out how the buttons, settings, and menus on your camera work. Practice turning the camera on and off. Practice changing shutter speed, ISO, and exposure compensation. Using a housing? Practice putting it together and shooting with it. The more comfortable you are with your gear, the more likely you are to capture the shot when it happens as you won't be fumbling around.
3) Make a Gear List
The open ocean isn't the place to learn you left a critical item at home. Make a list of what you'll need, such as batteries, memory cards, and O-rings, and use the list when packing.
4) Check Your Exposure
The very first thing to do once you are comfortably stationed in the cage with your camera turned on is to check your exposure. Focus on something light-colored (like the cage or the hang bait) and take a test shot. Peek at the photo and make necessary adjustments to your exposure (which will be easy since you diligently practiced Tip #2!). The light will change frequently, so do this often.
5) Move Around
The sharks can come at you from any direction. Shoot from different angles to capture unique images. Move around the cage and try various viewports. Just remember the rules of common courtesy and be respectful to the other divers.
6) Be There
Sharks are wild animals. No one can predict when they will arrive at the cages, what they will do, or how long they will stay. Putting in the cage time, even when it's slow or boring, is often the single most important factor in getting that incredible shot.
Answers to Common Questions about Great Whites
by Nikki Sevy
We've spent many years with white sharks, and have been putting divers into the water with them since 1998. Over all that time, we've learned a LOT about them. Here are the answers to some of the shark questions we’re most frequently asked by our great white expedition guests and online visitors...
How big do great white sharks get?
According to our friends at the Monterey Bay Aquarium White Shark Project, the great white pups are up to 3.6 feet (1.1 m). The adults get up to 21.5 feet (6.5 m), with the average adult growing to 15 feet.
Although sightings of great whites measuring over 20 feet have been documented at the Farallon Islands by members of the Monterey Bay Aquarium team, they have not been recorded on video... yet.
How long can a great white live?
In the past, many shark scientists believed white sharks only lived to be 30-40 years old. However, tissue testing done in 2014 indicates that great whites could live to be 70 or older. This means their lifespan could be about the same as a human.
Where do great whites live and swim?
White sharks congregate in areas with large marine mammal populations. They often hunt by ambushing their prey in an attack from the depths. Great Whites are highly migratory creatures, meaning they will travel great distances to mate and hunt. Scientific records show them swimming up to 2,000 miles at depths of up to 4,200 feet! Each year Pacific White sharks travel to an area roughly halfway between California and Hawaii. Known as “The White Shark Café,” researchers have yet to determine whether this is an area used for feeding, mating, or both. Although white sharks can be found on coastal shelves across the globe, there are only four major “hot-spots” for viewing white sharks in the wild.
What do great white sharks eat?
A young white will have a diet consisting primarily of coastal fish, skates, and rays. As the shark grows, its caloric requirements grow with it. Main prey items for adult white sharks include pinnipeds such as seals and sea lions. White sharks have also been known to dine on other sharks, stingrays, sea turtles, and even on dead whales. They will also sometimes snack on seabirds – Isla Guadalupe's white shark Rhett is a known seagull chaser! We've also seen the white sharks at Guadalupe feed on tuna. Thankfully, humans are not part of the white shark’s preferred diet.
Why are whites considered cold-blooded animals?
Like most fishes, a majority of sharks are cold-blooded, or ectothermic. Great Whites belong to a small group of sharks that possess some endothermic, or warm-blooded, capabilities. Although the white shark is technically cold-blooded, it has the ability to maintain a body temperature up to 15°F higher than the surrounding water. Their unique blood vessel structure is known as a countercurrent exchanger. This provides some major advantages when hunting in colder waters, including increased speed and mental ability. The other sharks which have endothermic capabilities are the shortfin mako, longfin mako, porbeagle, and salmon shark.
SENSE OF SMELL
Can white sharks really detect a drop of blood?
While white sharks have a remarkable sense of smell and can detect a drop of blood in 25 gallons of water, the myth of a shark smelling blood and immediately coming to attack is just that - a myth. Sharks actually use a variety of senses to locate their prey, including smell, sight, and the detection of electromagnetic fields. Anyone who's ever been waiting in the cage for a shark to appear knows that simply putting blood in the water isn’t going to bring in a frenzy of sharks!
Possibly the most important thing we’ve learned in 20 years underwater with these magnificent creatures is that their reputation as bloodthirsty killers is incorrect and undeserved. White sharks are fascinating apex predators who deserve our respect. Great White Adventures can help you gain a greater appreciation for them by getting you in the water to see these incredible animals up close. Once you do, you’ll be hooked!
WHAT ARE THE BEST PLACES TO SEE GREAT WHITE SHARKS?
by Ron Daniel
Where Can I Cage Dive with Great White Sharks?
There are just a few places around the world where you can go cage diving with great whites. Ranging from near to far, each of these locations host different populations and amazing views. Following are the best places to fulfill your dream of having the life-changing experience of being in the water with carcharias carcharodon, the incredible great white shark!
1) San Francisco, California
Just 29 miles west of the Golden Gate bridge, San Francisco's Farallon Islands play host to the 50 to 100 great whites who come to the island each year. These sharks come to feed on the resident sea lions and elephant seals. Although the waters tend to be cold and visibility can be limited, the huge average size of the Farallons' great white sharks makes it a coveted destination for shark lovers.
2) Isla Guadalupe, Mexico
150 miles off the west coast of Mexico's Baja California, Isla Guadalupe offers the clearest water views of great white sharks. From July through November, great whites can be seen in quantity as they come to feed on the Guadalupe fur seal and northern elephant seal. The smaller males show up early, energetically competing for prey and dominance. Later in the season, the larger females arrive, offering incredible views of these apex predators who can approach 20 feet in length! As an added bonus, the water temperatures average from 72° F in the early months to 68° F later in the year.
3) Cape Town, South Africa
A very dense population of great white sharks can be found two hours from Cape Town in Gansbaai. Known as Shark Alley, the waters between Gansbaai's Dyer Island and Geyser Island are teeming with great whites who feed on Cape Fur Seals. Also near Cape Town, Seal Island in False Bay is famous for great white shark breaching, as they launch themselves into the air during seal predations. Shark tours run to both locations all year long, with the peak season between June and September when the water visibility is best.
4) Port Lincoln, Australia
South Australia's Port Lincoln on the Eyre Peninsula is the launching point for great white cage diving trips to Neptune Islands Conservation Park. The park is Australia's only place to legally cage dive with great whites. There are currently three operators licensed by the government to run cage diving tours to view great whites. Best viewing times: Breeding season is December/January. Also, May through July offer excellent predation viewing opportunities, although it should be noted that this is during Australia's winter, and cancelled trips due to poor weather are not unusual.
AN OLD DIVEMASTER’S GUIDE TO PREVENTING SEASICKNESS
by Bruce Watkins
There's an old sailors' proverb that states, "The only cure for seasickness is to sit on the shady side of an old brick church in the country." While this whimsical advice is entertaining, it does not get to the heart of how serious seasickness may be, and how to prevent it. As to its seriousness, I offer the following true story...
How bad can seasickness really be?
During World War II, a friend of mine was ordered to ship from San Francisco to Australia. From the very outset of the journey, he was so seasick that it threatened his life. He could not eat or drink and was given intravenous fluids just to keep him alive. His torment continued for weeks. As his ship neared Australia, he was informed that an enemy submarine was patrolling the area. This deeply religious man, with unbearable seasickness, actually prayed that the submarine would sink his ship!
What causes seasickness?
While divers on charter vessels are not subjected to such extreme conditions, there are those that regularly afflicted by some level of seasickness. The cause of seasickness is simple — the confusion that is created when your eyes and inner ear do not provide equivalent information to the brain — although the cure is often elusive. However, the symptoms of seasickness can frequently be prevented by a simple behavior changes and proper use of medication.
How do I prevent mild seasickness?
For those who are infrequently or moderately affected, simply get a good night’s sleep prior to your trip and avoid excessive food, alcohol, and fluids. A moderate, low fat, bland breakfast is best. Once at sea, stay above decks if you can – preferably somewhere amidships where the boat’s motion is minimal. It also helps to keep busy, but always look at the horizon. Keep your attention focused on distant objects so there is less confusion in the messages your brain receives.
What is the best seasickness medication?
If you feel you need to medicate yourself, extensive study has been performed by navies throughout the world. They have all reached the same general scientific conclusions: Prescription formulations containing scopolamine (the active ingredient in the TransdermScop® patch) always come out as the most effective. The next best drug was cinnarizine (Stugeron in the U.K. but not available in the U.S). Coming in third were the over-the-counter and familiar medications: dimenhydrinate (Dramamine®), meclizine (Bonine®, Antivert®), cyclizine (Marezine®), and promethazine (Phenergan®).
How soon should I take seasickness medication?
The biggest issue with these drugs is deciding when to take them, as many require four to eight hours to become effective. If you wait until you are sick, these drugs will not help. This old divemaster’s advice it to begin taking the over-the-counter medication 12 hours before you sail, and then two hours before. (As an added benefit, they often help you sleep better.)
What are the side effects of seasickness medication?
Follow your doctor’s directions on prescription drugs. Importantly, every person is unique and reacts to drugs differently. Scopolamine, in particular, has many side effects, so be cautious. This old divemaster suggests not taking any of these medications for the first time while on a dive trip. Try them first ashore to see how you react.
How can I prevent seasickness without medication?
There are also many popular remedies such as wristbands and ginger. While some of these appear promising in some studies, they do not look promising in all studies. The US Navy, for instance, found that ginger did not prevent seasickness, but did make breakfast taste better the ‘second time around.’ There is, however, a psychological component to seasickness that should not be understated. If you truly believe a remedy will work for you, it probably will. Remember that diving is supposed to be fun. Find something that works for you and keep doing it. Remember too, that sickness often magically disappears when you get in the water.
Photo credit: Ron Daniel