Underway
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Specifications:
Length: 20cm
Breath: 40cm
Draft: 1cm
Hull: 4 drinks bottles - 2 outriggers, 1 holding the remote control gear & 1 for the trim rudder (cut in half)
Drive: 2 variable speed electric motors .
Power: 4 waterproof, flexible, thin-film amorphous silicon solar panels (1.2V and 330mA, 175mm x 60mm & less than 1mm thick) - two connected in series to each motor.
Control: (i) Rudder, used to trim the Puffin to a straight course, as the motors and panels have slightly different outputs. (ii) 3 channel remote control (stop, left & right) with a range of 30 feet, used (ideally) to swing a shading device over the arrays to change to speed of the motors to allow to puffin to turn.

PV cells, motor & propeller
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Notes on Design
Due to the low torque on the motor there were problems allowing the motor to run smoothly, the only solutions open were to gear the motor (slowing it down considerably and reducing its efficiency) or use flexible external mounting. The latter was chosen not only because this offered the highest revolutions on the prop. but it also negated the need to puncture the hull allowing me to keep the outriggers virtually unsinkable. The three hull design was used for maximum stability.

Note on the Maiden Voyage
1.The motor output was excellent for the needs of the model - even on a cloudy day it made headway against quite a stiff breeze. 2. Unfortunately, the shading device didn't work in the windy weather conditions on the day. 3. Although the three hull design was stable, it made Puffin very ungainly to lift and maneuver, both in and out of the water. 4. The motors proved to be too close to the water (one shorted out!). 5. Water proofing needs to be improved, generally.