Remote Controlled Boats - Styles of Hulls
The next great decision is which type of radio controlled boat hull to select. If your are setting up a scale project, your selection will obviously be determined by the full-size craft you would like to model. But sport, racing and sailing craft hull types display very unusual personality. In general, there are two hull classifications: monoplane and hydroplane.
MONOPLANES Monoplane hulls have one continuous surface in contact with the water. Monoplane hulls can be divided into 2 subcategories: deep-V’s and shallow-V’s.
Deep-V’s. Most monoplane hulls are deep-V’s. This traditional layout brings the keel to a sharp point well beneath the surface of the water. The underside of the boat is sloping upward steeply toward the hull’s sides, resulting in a radio controlled boat that knifes through the water with a comparatively large wetted surface area. This style of hull is stable at all speeds and provides sharper steering response. The downside is that the added hull surface that contacts the water causes drag that limits top speed. Still, with the right power system and proper tuning, these radio controlled boats are quite fast specially for newbees.
Shallow-V’s are the faster of the two monoplane types since they run with a lesser amount of surface area in contact with the water. The shallower keel vee-angle produces a flatter bottom that causes less drag. The downside is that a reduced amount of contact with the water means a reduced amount of stability, so they are more taxing to control and require more defined trimming. Shallow-v’s are very widespread for entry-level racing, this type of radio controlled boat or the so-called Crackerboxes being the most common.
HYDROPLANES Hydroplanes maintain more than 1 surface in contact with the water. They include tunnel hulls, catamarans, outriggers and stepped hydros.
Tunnelhulls are most often connected with full-size racing boats. They get their name from the raised center section of the hull. Two outer sections or sponsons sit in the water with a tunnel between them. As the boat gains momentum, air builds up in this tunnel and raises the boat higher out of the water. This reduces the surface area that contacts the water. This means less drag and higher speeds, while the relatively wide spacing of the sponsons maintains stability. This model provides a good balance of speed and handling for newbees.
Catamarans (cats) work on the similar principle as tunnelhulls and differ only in shape . They have more steeply angled sponsons much like deep-vee monos with a tunnel along the center. A catamarns tunnel tends to be taller and narrower than a tunnelhull’s, so it takes longer to preserve stability. These also, are a good beginner design.
Outriggers are at the highest of the performance ladder; their sponsons and main hull are separate pieces. This improves the airflow at high speeds, so outriggers are the fastest radio controlled boats; some even run at more than 90 mph! The hitch is that they are intended to work best at full throttle. At slow speeds, they sit too low in the water and do not handle well. Furthermore, they are the least forgiving when it comes to setting the trim.
Stepped hydroplane hulls have notches perpendicular to the centerline that part the wetted surface into 2 or more sections. These notches pick up the radio controlled boat up on step sooner, and that improves performance. At speed, these notches decrease the wetted area, reducing drag. This hull type includes a varied group, from plain deep-v’s with minor steps in the hull, to three-point hydro racers such as the full-size Miss Budweiser turbine-powered, unlimited hydroplane. At full speed, three-point hydros ride on two small areas of the forward sponsons and the centrally situated propeller at the back.
Any way you look at it radio controlled boats are a wonderful way to spend a sunny afternoon. Take the time to enjoy the hobby and spend time with your family and friends.
