Advanced DuckyBots: Making Real Robots

Make sure your duck floats!

Plug holes
Fill with Construction foam
This also allows you to cut out areas to insert waterproof boxes for electronics

The Brain

Microcontroller to turn motors on, react to sensors etc.
Arduino is a good choice and comes in many flavors including with built in wiFi, bluetooth etc.
Lego Mindstorms (careful though! expensive and hard to waterproof.

Most motors will work (for a while) in fresh water, or extend the propellors. You can buy RC boat propellors online (ebay, amazon, etc) with long shafts.
Playmobile underwater motors (connect wires instead of using batteries)
You can use one motor and have a servo controlled rudder, or just use two motors for tank style steering.

Arduino motor shields are the easiest and allow for reversing. Some do not support low voltage motors however (read the specs.)
A mosfet transistor can turn the motors on and off (and are very cheap)

Position: Many GPS modules are available
Light, distance and many other also available. See: http://playground.arduino.cc/Main/InterfacingWithHardware#Input

http://robobrrd.com/
http://letsmakerobots.com/
http://sparkfun.com -- Kits, Arduinos, sensors, etc.
http://ydielectronics.com Local (Needham street) electronics store, carries lots of Adafruit, Sparkfun and other Robotics parts, Also many educational kits
http://microcenter.com -- Cambridge store that also has a diy electronics section.
http://adafruit.com -- similar to sparkfun, also lots of educational content on http://learn.adafruit.com
Your instructor: kevin.osborn@gmail.com http://baldwisdom.com