FAQ

All planing boats, with speeds over 20 knots. Anything from PWC water scooters, to fast superyachts.

Petestel is not a stepped hull in the traditional sense of having transversal steps in the hull, to increase angle of attack and provide air bubbles under the hull surface. However, Petestep’s deflectors can be combined with a stepped hull to get the advantages from both worlds, if desired.

Petestep is working in close collaboration with the boat designer and boat builder to create the best possible boat. We are convinced that the synergies created by having people with different specialities are the future. By using our patent combined with detailed specifications of how the boat is intended to be used, as well as thorough weight calculations and advanced performance simulations, Petestep can optimize a boat model further than other hull designers and Naval Architect firms.

Yes, we have done over 250 full scale tests, and driven around 100 different prototype versions based on 24 foot sport boats with outboard engines. We have always measured the boats’ running attitudes, motions, GPS-data etc, and analyzed the data as reference to our simulation software.

We have also done specific research on the spray behaviour on V-bottom boats and its interaction with deflectors. On this topic, University studies have also been made, which verified our potential to reduce resistance.

Yes, all conventional propulsion systems work with Petestep deflectors.

Since Petestep is a patented technology, we charge a small license fee per boat produced. This fee is earned back several times over solely by the ability to use smaller engines, In addition, lower fuel consumption, lower noise and softer ride helps lower the lifecycle cost even further, over time.

A planing boat is designed so that at a certain speed, a large portion of the hull lifts above the water surface, significantly reducing hydrodynamic drag. Once the boat reaches planing speed, hydrodynamic lift allows it to “ride” on top of the water instead of pushing through it. This means that increased engine power directly translates into higher speed—unlike displacement hulls, which reach a natural speed, as they are rather pulled into the water than lift out of it.

Fuel consumption for a planing boat is typically highest just before and during the transition to planing (the “hump”). Once fully on plane, fuel consumption per nautical mile drops (or MPG increases) because wetted surface area decreases. The most fuel-efficient operating range is usually just above planing speed. At higher top speeds, resistance increases and engines lose efficiency, leading to sharply rising fuel burn.

Many modern fast boats use waterjet propulsion instead of conventional propellers. Waterjets allow high power density, shallow draft, high propulsive efficiency and exceptional maneuverability. They reduce the risk of underwater object damage and enable rapid directional changes—critical in coastal and archipelago environments. Petestep tailors each hull for the propulsion to ensure optimized performance.

Petestep reduces vertical accelerations (slamming forces) by up to 30–50% and can reduce drag by 5–40% depending on vessel size and operating profile. Reduced drag improves fuel efficiency, range, and top speed. Additionally, spray is redirected downward and aft, resulting in a drier ride and reduced visible and radar signature.

By eliminating traditional spray rails and reducing impact loads, Petestep hulls significantly reduce G-forces in heavy seas. This lowers crew fatigue, reduces structural stress, and enables higher average speeds in rough conditions.

Lower hydrodynamic resistance increases operational range and reduces power need and fuel consumption. Lower impact loads reduce injuries, wear on engines and structural components, decreasing maintenance costs and improving total lifecycle economics.

Yes. Petestep technology is production-method agnostic and can be implemented in fiberglass, carbon fiber, sandwich composites, aluminum, or HDPE without limiting material selection.

We model the boat using over 50 parameters, including deadrise angle, weight, Center of Gravity, projected aerodynamic area, etc. All forces acting on the boat are calculated for a certain speed. This allows us to run the boat in multiple speeds and adjust the hull and optimize it for a certain boat and its usage. We use these results as input to our high fidelity CFD simulations.

Of course, every boat is a trade off. E.g. between weight, cost, performance and interior space. You can’t have it all. Therefore, a hull has to suit the boat model’s intended use. If the boat is a fast offshore military boat, it might be ok to be a little heavier and more expensive. On the other hand, it the boat is to be used by the mass market with friends on a lake a couple of times per year, it should probably have as much space as possible for the money.

When the concept is figured out and the priorities are set, all parameters of the boat should be optimized to get the best boat possible. The chine beam, center of gravity, deadrise, engine power, just to name a few parameters, are optimized to get the best performance possible. At Petestep, we use advanced computer simulations that considers the exact pressure distribution under the hull bottom, in order to create the best trade-off possible

Petestep is working in close collaboration with the boat designer and boat builder to create the best possible boat. We are convinced that the synergies created by having people with different specialities are the future. By using detailed specifications of how the boat is intended to be used, as well as thorough weight calculations and advanced performance simulations, Petestep can optimize a boat model further than other hull designers and Naval Architect firms.

For planing hulls, our simulations are more reliable than towing tank simulations because of no scale effects. We can even run wave simulations and high-speed turning with very high confidence.

Planing boats typically feature shallow-V hulls, deep-V hulls, or variations between the two. Shallow-V bottom hulls plane quickly and are stable in calm, shallow water, but can produce harsh impacts in rough seas. Deep-V hulls cut through waves more effectively, offering smoother performance in offshore conditions, but usually require more engine power to plane. A Petestep hull gives the best of both worlds – the ride of a deeper V hull, and the efficiency of a shallower V hulll.

In one way you should use as little engine trim as possible. A neutral trim will make the boat less sensitive to waves and will make it easier to steer at high speed. It is also true that if you trim the engine up or down a lot you will lose thrust. But in planing V-bottom boats, the most important thing is that the boat has a good angle of attack. As soon as you get over the hump, the bow will drop downward with increasing speed. But you want to keep the boat close to its optimum trim angle. This will require you to trim the bow down in low speed close to the hump, and bow up, at high speed.

Usually a good angle of attack is around 4 degrees, but it depends on speed. On Petestep boats, different deflectors are optimized for different angles of attack, at different speeds. If the engine trim is not used correctly, the deflectors will not be optimally functioning but they are designed to have better performance than a comparable spray rail hull in every situation.

All full planing boats can benefit greatly from a Petestep hull. However, the technology is such an integral part of a boat model that it needs to be in the design right from the start. The technology can’t be retrofitted or transferred between boat models. Manufacturers work in cooperation with us to develop a boat with the best possible comfort and performance. We make sure the hull is optimized for a particular model and put restrictions on the placement of equipment and tanks etc. Petestep charges a fee for the design and development, along with a license fee for each produced boat. Petestep keeps in regular contact with the manufacturers to ensure the boats are being produced according to the specifications.

More and more manufacturers are becoming interested in our technology. If you are a manufacturer and want to get in contact click here.

If you are a consumer, maybe your local distributor will have a Petestep boat soon. Next time you buy a boat, ask for one with a Petestep hull!

Any planing boat can be made softer, even without changing the deadrise angle. The beam is an important parameter here. If the beam is decreased by 10%, vertical accelerations will be decreased by about 20%. However, the boat will also lose side stability by more than 10%.

Petestep can make this design dilemma easier. If a boat uses a Petestep hull, it can be wider, have the same vertical accelerations and significantly increased side stability. Or, it can be just a little bit narrower and with a decrease in vertical accelerations by half, while having the same stability.

A boat can be made softer in waves in a variety of ways. However, each method leads to other effects:

• Less beam (decreases stability, increases hump speed and limiting space)
• Adding weight (linearly increasing fuel consumption)
• Increasing deadrise angle (increasing fuel consumption)
• Using Petestep technology (decreasing fuel consumption and quieter ride)

Decreasing the beam is often not a good idea because decreased stability and space is never desirable. To achieve a reduction of vertical acceleration (hardness of ride) by 30% using conventional technology by adding weight or increasing the deadrise angle, around 50% more energy is required and hence, 50% more fuel consumption.

Petestep technology always gives a boat a significantly softer ride, and/or significantly lower fuel consumption. We can make a boat ride over 30% softer, while also reducing the resistance by 5-10%. Compared to a boat with similar softness using conventional technology, resistance is now reduced by over 35%.

There is no deadrise that works better or worse. We have done boats using moderate ~12 degrees to very high ~27 degree deadrise boats and they all have lower resistance and softer ride than a conventional hull with the same deadrise.

For most planing V-bottom boats, optimal angle of attack at cruise speed is around 3 degrees. Proper engine trim is essential to maintain this balance. Excessive trim increases drag, slamming forces in waves and reduces thrust efficiency. Too low trim also increases drag, and lowers dynamic stability and can cause bow-steering. Maintaining the correct trim ensures maximum hydrodynamic efficiency and stable high-speed handling.

Critical. For optimal performance, the center of gravity should typically be located around 33% of the waterline length from the stern. Incorrect weight distribution—especially too much forward weight—can increase drag, delay planing, and raise fuel consumption. Petestep always matches the center of gravity location to the hull and the specific boat model.

A concave or uneven hull bottom increases hydrodynamic resistance. Even small irregularities act like permanently deployed trim tabs, increasing drag and reducing efficiency. A straight, smooth hull bottom allows clean water flow and maximizes planing efficiency.

Petestep technology is applicable to all planing hull designs, but should must be integrated during the design phase. It can be retrofitted onto existing hulls, but this is much more labour intense. Every hull isbe specifically optimized for maximum efficiency and performance.