This picture shows a drag surface run test 
for a early forerunner of CSSX with 12 m long 
and 35 t displacement. Model in sclae 1 : 10,5

As you can see the bow wave climbed just over 
the deck at a speed equal to 6,5 to 7 knots. 

If you go for higher speed on the surface 
with this model - the drag increase dramatical 
and the sub start to dive dynamic with empty softtanks.. 

For the test you need : 

- a friend
- a timer clock
- a spring scale 
- a piece of wood
- a ponton with metrics marks 
- a fiendly day whithout to much waves 
- a nice lake
- a precalculation of the model scale and speed
  so you can make the model in a maximum scale 
  depents on the maximum speed you friend can run 
  over say about 33-66 feet at a constant speed. 

and of course a scale model which is able 
to trim at the right waterline. 

If you want to test higher speeds - you need
a motorboot to run and a 
GPS system for speed control..  

Carsten