Since my big boat sailing season has come to an end, and I’ve had a little more free time, I decided to aggressively explore a corner of the box, specifically weight. My goal was a displacement of sub 200g. In reality I was attempting to explore numbers that work for larger classes at a footy scale.
My final numbers for this quick and dirty design into light footing are:
LOA = 341.25 mm
LWL = 338.1 mm
B (on deck) = 56.7mm
B wl = 56.51
Displacement = 182 g
This produces a DLR of 136.37, which by big boat terms is potentially pretty quick.
To achieve these numbers I constructed the boat out of 2mm depron with minimal internal reinforcement. I’ve used a Carbon Fiber helicopter blade for the keel fin, which in retrospect is much too heavy at 18g, but the weight is in an acceptable place so I’ve decided to keep it. I have used my standard battery arrangement, which is a 1200mah lithium ion digital camera battery with vac formed holder (14g), a 6 gram rudder servo and a stronger sail servo that tips the scales at 12.6g. I rounded out the whole with an 80 gram keel bulb for a ballast ratio of ~ 44%
The boat is a slight double diagonal, with the transom angled down in the box. The hull is chined with a 4 piece hull construction, with the transom set slightly forward of the extreme end of the boat so it has a quasi sugar scoop. With everything bonded together I was astonished at how stiff the panels are. Actually much stiffer than my vac formed Red TYDES, which to me means the boat is over built. However, from conception to sailing, total time was less than 12 hours.
As is usual with something like this, I started out thinking this would be an excellent light(er) air boat, however the calm winds that have prevailed recently gave way to stronger breezes of 10-15kts. It was a true trial by fire. As expected the boat was a bit difficult to tack, however with some careful planning and set up, you over sheet the sail as you ease the rudder over and I had about a 90% success rate in today’s wavy/choppy conditions. I will say when sailing close to shore with a bit of rebounding breeze E.L.F. was incredibly responsive. The jury will be out until I can line up against at the very least a RED TYDE, until then I’m not giving up on it.
If anyone wants the hull panel developments and further build notes please let me know I am happy to share.