The Technology Behind the Amphi

The Amphi team has simplified the powered underwater propulsion to the ultimate level. Our powered bionic monofin encapsulates two common personal modes of underwater propulsion in a single device. It contains advanced sensors and electronics to assist you with your dive and after-dive analysis and works as if it was a part of your body, it needs no attention. You are free to enjoy your dive or swim. The power is with you or to be precise - behind you. In this blog, we are going to go through the key aspects of the Amphi.

Key Technological Aspects of the Amphi


The central idea behind the Amphi system is hybrid propulsion powered partially by human muscles and partly by electric thruster. Does this concept sound familiar? We see the same approach on our streets in the form of an electric bike. You may be wondering why one would build a powered bionic monofin. Wouldn’t it be better to use a good pair of fins or an underwater scooter? Well, the answer to this question is: it depends. If your goal is to minimize the weight and complexity, then fins are the way to go. The downside to using a pair of fins is that you are quickly exhausted and less accessible to air. 

If you want to maximize your bottom time and minimize effort, a powerful (and heavy) scooter is the best choice. Realistically, dives are somewhere in between. You are rarely forced to be super light and reliable or to be towed by a behemoth without any effort on your part. Ideally, you want something in between, a smooth transition between muscular and artificial propulsion. The Amphi delivers exactly that. It shares the effort between the diver and the thruster, and you can decide how much support you need. The fin and the scooter are integrated into a single device, adding other advantages that are not possible when using fins and scooters.

the mechanical Advantages

Boats have propellers mounted at the stern or near the stern. The reason for this is that it interferes with the haul. Ideally, you want your thruster to exchange the energy so that it creates thrust, not drag. Hitting the haul with the jet coming out of your thruster creates unnecessary turbulence and drag. The same is true for the diver. Holding a propeller in front of you creates interference with your body. You may minimize it by lowering the scooter and riding above it, but in this case, you generate more drag by being beyond the hydrodynamic shadow of the scooter. In addition, the line of thrust and the line of drag are not co-axial, and it creates torque, which throws the diver-scooter system of balance and needs to be compensated for, thus causing additional energy losses. 

Amphi places the propeller at your feet. Yes, the fin blade is behind it, but the blade is much smaller and smoother than your body and diving gear put together, so the drag created by the fin is way smaller. This configuration creates an additional hydrodynamic advantage, which I will write about later. And yes, you guessed it, the line of thrust and drag are co-axial. 

Another mechanical advantage is integration. We use the same mechanical structure which holds and attaches the fin to your feet to support the thruster. We don’t need handles, controls, anchoring points. The Amphi weighs close to ten pounds. Similarly, power-wise scooters weigh around 16 pounds. Keep in mind that Amphi already has a fin, which for a traditional diver adds another couple of pounds. Pound for pound, Amphi is roughly two times lighter than the scooter-fin combination. 


How does the propeller work with the fin? It is just two separate thrust generators put randomly together, or something else? Well, the answer is: this is something entirely else. There is a synergy between the two. The secret sauce of Amphi propulsion, if you will!

I need to be a little technical here, bear with me. I will try to stay at a fundamental level. For now, let me focus on the fin's angle of attack (AoA) and flow velocity through the fin blade. With any fin, the angle of attack is changing throughout the stroke. The closer to the end of the stroke (where the fin changes its deflection from one side to another), the higher the AoA. At the end of the stroke, the vertical velocity VFin is the highest. This vertical velocity VFin, together with swimmers velocity Vs., contributes to the flow velocity V through the foil (fin), see the diagram. Sadly, with this large angle of attack α > 40 degrees (especially at low swimming velocities and strong kicks), the fin cannot take advantage of the vertical velocity amplitude. It is similar to a wing stall. It generates no lift on the foil, thus no thrust either. So, the potentially most powerful moment of the kick is virtually powerless. In Amphi's propulsion, the angle of attack is changed by the thruster's jet. It decreases it by providing an additional vector Vt parallel (for the most part) to swimming velocity Vs and skewing the overall flow V vector towards lower attack angles. This prolongs the lift generation phase of the fin. What is even cooler, it decreases drag on the fin too. Drag is usually minimal for small angles of attack. Sometimes it feels almost as if the fin wasn't resisted by the water at all. In addition to the AoA magic, the thruster provides much higher velocities over the fin surface, which creates lift proportional to V2. As I said, I will be talking about this stuff more in later entries. If this was too much for you, then remember one thing: we can increase thrust created by the fin by roughly 10—20% by providing synergy between the propeller and the blade.


How about no controls whatsoever? Is there anything more comfortable than “a perfect nothing”? No push buttons, dials, cables, gauges, levers handles? Nothing, nada, zip. You attach your feet to the Amphi and swim. Amphi will sense the strength of your kick and will add or subtract power accordingly. You can change the character of this control mechanism in two ways: by changing sensitivity to your kicks, or by changing for how long the thruster will remain “on” after you stop kicking. This allows you to go between aggressive sport like machines and relaxed cruising pal. 

Other aspects of ergonomics are the SPD clips we used instead of traditional foot pockets. The clips achieve three things:

Amphi can be disassembled into a fin blade (2 pounds), bindings (1.5 pounds), PowerPack (6.5 pounds). You can place them in separate bags or a single monofin bag, like those offered by Waterwayfins or similar. Easy to travel with as long as you remember that the bag is 30 x 30 inches. 


What’s more important than being able to share the system with your loved ones. Amphi can be turned from a powerful and very dynamic machine to a toy just by its software. Using your phone app, you can change almost anything within the system. But this is not where the flexibility ends. One can change the powerpack and blades. Examples: strong powerpack and shortfin blade for mostly powered dives or smaller powerpack and long flexible blade for relaxed long swims mainly using your muscles. And anything in between. 

We plan on having three different power packs and six types of blades. The only constant is the bindings, well, you can get different colors, though. 

On-board intelligence

By now, you know that Amphi has its electronic brain. A pretty powerful one, too. It can take inputs from multiple sensors to control your swimming actions. But it can also track your underwater path (including position, speed, and depth) if you want to, and then display it for you on your smartphone, or share it on the Internet.

In the future, we will add an optional sensor suite called MyGaya to record oceanographic data. But it’s a separate subject. The bottom line, Amphi, is an intelligent dive buddy. It’s not a dumb towing aid. 

UW to the cloud

The significant part of this project has been allowing people to share their underwater experiences online. Thus Amphi is capable of communicating with the cloud via the user’s cellphone. One will be able to sync Amphi’s data to user servers, share them on forums and with friends, compete remotely, etc. The possibilities are endless. We did not even scratch the surface yet. The wifi connectivity is there, and how people use it will be mostly up to them. We, the Amphi team, will follow the popular vote.

Amphi Americas - The World's First Powered Bionic Monofin

If you are interested in learning more about the Amphi, connect with us today! 

Critter Feature: Grey Reef Shark

The gray reef shark, also known by the scientific name Carcharhinus amblyrhynchos, is most commonly found living in the Indo-Pacific Oceans, specifically between Easter Island and South Africa. They can also be found in the Caribbean and spend the majority of their time dwelling in the ocean’s beautiful coral reefs. Although there are some distinct differences between the grey reef shark and the great white shark, these shark species are commonly mistaken for one another. Fortunately, there are some key features that make telling these two sharks apart much easier. For instance, grey reef sharks are usually much smaller than great whites, often growing to be just 6 feet long or shorter. These aggressive, yet social sharks make up a large part of the marine life that live in these coral reefs. To learn more about grey reef sharks, take a look below!

Grey Reef Shark Features

Grey reef sharks are often confused with great white sharks, but they do have distinct features that make them unique. Just like great whites, grey reef sharks have large, round eyes, long snouts, and the classic grey upper body and a white underbelly. However, grey reef sharks are a medium-sized shark, weighing in under 75 pounds, and they have a distinctive caudal fin (tail) which has a broad, dark band that runs through it. Also, these sharks are known to develop a darker top color due to sun tanning when swimming in shallower waters. Some of the grey reef shark’s fins may also have darkened tips that help them stand out from other shark species.

Grey Reef Shark Behaviors and Habits

Grey reef sharks tend to dominate the reef with their aggressive behavior and hunting instincts. They are very agile predators thanks to their fast-swimming capabilities as well as their ability to dive up to 33,000 feet, although they typically remain at a depth of around 200 feet. Most commonly, grey reef sharks feed on bony fishes and cephalopods such as squid and octopus. As a social species of sharks, grey reefs travel in schools of 5-20 sharks and often hunt either alone or in a small group. This allows the sharks to have the run of the reefs, threatening most other species that live there. Some have even seen grey reef sharks corner entire schools of fish into a wall along the reef, exemplifying their hunting skills.

Learn More With Amphi Americas

Amphi Americas is dedicated to advancing underwater technology and capabilities, not only for those who enjoy diving but also for the wildlife that lives in our oceans. If you are interested in learning more about our product or would like to gather more information about our training, vacations, and seminars, connect with Amphi today!


Travel to Curaçao for Diving and More Fun

Curaçao is a Dutch island located about 40 miles from the Venezuelan coast. It’s well known as the “C” of the “ABC” Caribbean islands, followed by Aruba and Bonaire, and is a popular tourist destination thanks to its many amenities. As a tropical island with beautiful beaches and coral reefs rich in marine life, it’s no surprise that Curaçao is renowned for its incredible dive sites and underwater explorations. And the Caribbean island of Curaçao offers the experience of a lifetime for everyone to enjoy. From unique architecture and landscapes to the warm ocean water, Curaçao provides fun and relaxation for all. See why so many are flocking to this extraordinary Caribbean island, plan your next adventure, and experience diving in Curaçao! 

curacao diving


Learn More About Curaçao    

If you’re planning a trip to Curaçao, then you may want to learn a bit more about the island. For instance, Curaçao should be pronounced as “cure-ah-souw” and the most common languages spoken here are Dutch, English, Portuguese, and Papiamentu. Most travelers aren’t aware of Curaçao’s Dutch background, but it shows dramatically throughout the island. Some other unique features you’ll notice while visiting Curaçao are the brightly colored buildings, which are iconic in colonial architecture, and the weather and water here are warm year-round. Also, Curaçao is mostly unaffected by the Caribbean’s hurricane season due to its prime location on the southern edge of the island’s hurricane belt. 

Curaçao is a paradise for the whole family thanks to the spectacular beaches, fine dining, shopping, street fairs/parties, and most importantly, it's diving opportunities. 

Curaçao Diving  

Diving in Curaçao is truly an experience you won’t want to miss. It’s known to have healthy, bright coral reefs full of unique marine life as well as sloping walls and historic shipwrecks ready for novice and expert divers to explore. Whether you’re an experienced diver or new to the ocean, Curaçao provides open waters perfect for beginners and advanced divers! And, you’ll also get to see wildlife such as sea turtles, eagle rays, sharks, eels and lionfish as well as some island natives like the yellow-spotted sand goby and the spotted four-fin blenny. Because the waters are warm year-round and there is a very low chance of a hurricane hitting this spot, Curaçao is commonly visited at all times of the year. 

Take a trip to this popular Caribbean island and check out some of the best Curaçao diving sites! This may also be the perfect time to upgrade your diving equipment with a powered, bionic monofin created by Amphi Americas. Check it out here today!

Creature Feature: The Queen Triggerfish

The Queen Triggerfish, also known by the scientific name Balistidae, is a native fish of tropical areas such as the Caribbean, Bermuda, and the Gulf of Mexico. Although triggerfish are commonly described as being aggressive and mean, they are often captured and put into the aquarium trade due to their attractive appearance. Unfortunately, this has put Queen Triggerfish on the vulnerable species list and is now at a greater risk of becoming endangered. This fish species not only has a unique appearance but has many other qualities and abilities that make it a treasure for our oceans.

queen triggerfish florida

Queen Triggerfish Features

The Queen Triggerfish is best known for its unique ability to lock themselves into small hiding spots with their spines to stay safe from predators. Their extraordinary spinal features allow them to lock into a tight space using their first spine. Once the second spine depresses, it acts as a “trigger” to unlock the first spine and allows the fish to swim free. This is also how the fish received the name “Queen Triggerfish.” 

As mentioned before, triggerfish are commonly sought after for their aesthetic appeal. Most Queen Triggerfish is triangularly shaped and are a yellow and green color with interesting lines circling the eye. Some triggerfish may also have blue or purple on their fins and in other areas, and have a fanned, indented tail shape. 

Queen Triggerfish Behavior and Habits

Queen Triggerfish are commonly known as being aggressive and often wreak havoc in the reef during feeding times. As bottom dwellers who dig out their prey to feed on, triggerfish have become adept at using their fins to move away debris to locate their prey. Then, they use their strong teeth and jaws to bite through tough, hard shells of crabs, shrimp, sea urchins, and clams. Other sea creatures that triggerfish will feed on are squid, worms, and krill. Because of how hostile and fierce the triggerfish can be with their prey, smaller fish often follow behind to pick up their leftovers!

Learn More with Amphi Americas

Amphi Americas is dedicated to advancing underwater technology and capabilities, not only for those who enjoy diving but also for the wildlife that lives in our oceans. If you are interested in learning more about our product or would like to gather more information about our training, vacations, and seminars, connect with Amphi Americas today!