What boats will benefit from Petestep’s technology?

All conventional fully planing V-bottom boats produce a lot of spray to the sides. As long as there is a spray flow, there is energy to recover, making it worthwhile to use a more optimized hull. In normal situations, planing boats up to 15m can benefit greatly by using Petestep’s technology.

Is Petestep a stepped hull?

No, despite having “step”, in the name, Petestep has nothing to do with a traditional stepped hull. Stepped hulls are efficient at high speeds (~30-40+ knots) due to the inherent trim the step creates. Unlike normal V-bottom hulls, the bow of stepped hulls does not drop down at high speed. As a bow drop is associated with increased wetted area and more frictional resistance, the stepped hull can help avoiding this effect.

It is possible to integrate Petestep with a stepped hull to get more top-end performance in high-speed boats.

How does Petestep compare to a traditional hull designer

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.

What constitutes a well-designed hull?

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

Why is engine trim important?

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.

How does your design tool work?

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.

Have you done any research?

Yes, we have done over 150 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, a University study has also been made, which verified our potential to reduce resistance.

How can Petestep reduce resistance by 35%?

Compared to a clean V-bottom hull, Petestep technology can reduce resistance by about 35% by removing a major part of the wetted surface and adding lift and thrust to the hull, while providing a significantly more comfortable ride. And compared to a spray rail hull with the same level of comfort, a Petestep hull has about 35% less resistance, by using a smaller deadrise angle.

Also, see “What is the connection between soft ride and fuel consumption?”

How does Petestep develop a new boat hull?

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!

What is the connection between soft ride and stability?

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.