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May 21, 2020

Float kits are slender floats that are installed under the main body of small planes, like a Cessna C180 for example. These planes have a narrow body, and thus can be transformed into seaplanes by adding float kits under them. This blog will discuss float kits in a bit more detail to help you understand what components these float kits are made of that enable a plane to float on the water.

Watertight compartments

Float kits for seaplanes are supposed to make the plane float on water, so these kits can not afford to get filled with water. If this happens, the float kits will sink into the water resulting in the plane sinking too. To avoid this, there are separate compartments within the cylindrical-shaped float kits. These compartments are watertight, which means water cannot enter them even if the float kit is punctured or gets cracked.

These watertight compartments in the float kits make the kit float even after it gets cracked or punctured at any point.


Float kits have a backbone seam, or ‘chine’, on each side of the hull or the pontoon. The chine plays the role of a separator between the sides and bottom of the float kit. This chine also plays a very important role in pushing the water away from the surface of the float kit, and helps the plane in floating in a better way, avoiding the float kit from sinking in water. The chine provides stability to the seaplane floating on water. It helps keep the seaplane above the water by lifting it upwards while floating forward.


The keel is a structure that acts as a support to the bottom of the float kit. It is an extended slit-like structure that is exactly at the center of the flat kit bottom. It runs from the front to almost the middle of the float kit. The main purpose of it is to enable the pilot to float the plane in a straight line. You can say that in this way it enhances the stability and handling of the seaplane. The keel actually provides resistance against the sideways motion and in this way, it supports the plane to keep a straight path.

Water rudder

In the case of most seaplanes, there’s a water rudder that’s attached to the stern of these float kits. As the name suggests, the water rudder plays pretty much the same function as the rudder plays a role in airplanes. The water rudder is installed with rudder pedals. It enables the pilot to control the plane and steer it to keep it on a desired path. A water rudder is very important because it’s proper functionality is the determiner of the successful floating of the seaplane. The rudder makes sure that it reaches the predefined destination, which is sometimes the sky, and does not end up in ‘no man’s land’.


A skeg is a short extension of the keel at the bottom of the float kit. It’s a small but very important component that makes sure a seaplane floats properly and doesn’t tip backward to the rear end of the float kit. It keeps the plane standing on its front end and prevents it from flipping backward.


The step is the portion in the bottom of the float kit that’s between the keel and the skeg. The step introduces a change in the shape of the keel. When the keel ends, the shape and angle of the step move upwards. This upward angle prevents the plane from flipping backward when the pilot picks up speed and the plane starts lifting up from the front side.

These components enable float kits to keep the plane floating like a ship on the water. The precision, quality, and consistency in the manufacture and installation make sure that seaplanes remain floating on the water in a steady, comfortable, and safe manner.

About Acorn Welding

You cannot get more experienced, professional, and skilled experts than Acorn Welding, offering international standards and best quality to keep your planes floating like birds on the water. Visit our website to learn all about our services and products.