Floats or seaplane pontoons are a landing gear adaptation for an aircraft in which existing wheels are removed and replaced with hollow pontoons, supported by struts and spreaders, and attached to the fuselage with fittings that usually use the landing gear points.
Your airplane must first have a “seaplane kit” in it. This usually consists of fuselage beef-ups, and a vee-brace in the cockpit. If the seaplane kit is already in the plane, installing floats for the first time will take from one to three days. After that, changeovers between wheels and floats can usually be done in a few hours.
What are they made of? Over the years floats have been made out of wood, aluminum, fiberglass, composite or even fabric. The best service seems to be achieved from the aluminum, some still in service for 50+ years! Tough, fexible, easy to repair, light, and relatively inexpensive, aluminum meets the varied and critical demands of water takeoffs and landings. Boats are one thing; airplanes are another. Seaplane pontoons live in a world between the two, and must take the beatings delivered by both worlds. That’s why aluminum has been the standard for floats for over 50 years.
Floats come in all sizes and styles, and are “certified”, which means the FAA has approved them for installation on a specific type of aircraft, or “experimental”, which remains within the world of homebuilt airplanes. Aqua Floats are both certified and experimental. So you can even float your kit-built airplane!
What about wheel floats or “amphibs”? When floats are built with wheel landing gears built into them they are called “amphibious” or just “amphibs”. Hydraulic wheels in the nose and underneath the floats allow the plane to land on both land and, (when retracted), water. While amphibious floats give great versatility to an airplane as far as landing options, there is a significant trade-off. The added weight of the wheels means the plane can carry less ….. referred to as “useful load”. Performance of the aircraft may be affected, and the price and maintenance of wheel floats is significant also!