Different strokes.....

   ‘So what do model boats look like then?’  My wife tells me that all of my boats  look the same but she’s not easily convinced.  There  are  few   basic  classes  but  there are also hybrid and  variations   within   each group   that  should  cover all other eventualities.   In the description the term  ‘on   the  plane’ is mentioned quite a lot. 'On the Plane or Planning' means  that  when the boat is travelling at speed the  boat’s hull has risen up out of the  water   and skimming over it or ‘planing’  on the surface.  The less of the boat  that is in the water,   the less drag (or resistance) there is on the hull  and the faster the boat will go, ( air offers less drag than water ).


   Oldest of all boat shapes ( apart from the Ark ) and developed  over hundreds of years until now a class 1 off-shore power-boat can  sustain  speeds  well over 110mph.  The dihedral form  hull  provides lateral  stability as the hull leaps across the water.  ace boats can have any  number  engines,   one race boat in 1990 had seven!   Handles well in rough weather.  Variations are hard chine, shallow or modified Vee.

Multi boats are shallow Vee boats and are popular for racing in the UK but are  not based on any type of full size boat.  Multi boats are fitted with very  powerful engines,  the hulled is shaped so it is very stable on  the straight  and  then is capable of turning very sharply.  I have owned  two multi boats but I prefer real model boats!


   Twin hulled boat joined by a ‘wing’.  Now currently the  most highly developed hull form and used by all top off-shore racers. The  hull rides on the flow of air through which provides lift similar  to an  aeroplane’s wing thus raising the hull up out of the  water.  Performs  best   in  calmer  waters.   Racing catamarans usually have  two  or  four engines  down   in the twin hulls or sponsons.  Variants are trimaran  and mono-cat.

   Small one-man version of the catamaran.  Raced inshore   on   calm   waters.   These are the boat worlds equivalent of Formula  One  cars.   Driver   tilts  the outboard engine to trim the boat  for  fastest  speed.   These   boats  reach  over 100 mph in less than 5  seconds,   can  turn   on  a  pinhead and pull “4 G’s”  into a corner.  Not for the  faint hearted.

Fastest of all types of boats,  the full size ones easily  reach over 200 mph being driven by aircraft engines or  helicopter turbines.   The boat rides on only three points,  the tips  of  the  front   two  sponsons and the propeller.    As the boat fly over  the  surface  of   the water,   they require a ‘turn fin’ to hold them from sliding  sideways in  corners.   The full size boats can only turn left,   the models   only right as the model engine run in reverse to the real thing.  ‘Hydros’  can only run on calm water.


An uncommon boat type has wings fitted under the hull  to  lift the boats hull clear of the water.   The wings of foils support  the   entire weight  of the boat when passing through  the  water much  like an  aeroplanes  wings does while flying through air.  The foils take many different  configurations,  some even have computer attitude and pitch control. Stability can be a problem in models.

AIRBOATS or swamp boats.

   Usually a flat bottom type boat with a large  aeroplane propeller on top.  Ideal for weedy water  and  even  snow as the boat usually uses air rudders.  Air boats with water rudders handle much  better but defeat the object of flat bottom boat if that’s what  you want.  A  large,   fast and unprotected  propeller  at ground level can be very  dangerous so the modellers need  to  take  great care of  themselves and everyone nearby especially water  fowl, put some sort of guard or cage around  the prop whenever possible.   Hovercraft  also  come somewhere  in this category but finding a practical commercial kit is not easy.

More Reading...

Surface-Piercing Propellers-By Paul Kamen

Getting Started in RC, RC Boats


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