Rationale Report

OVERVIEW
The selection for the propulsion system modeled above was a fairly simple choice. This system, which includes a single drive motor driving the back two wheels and a propeller, is the most efficient use of the allotted motors. Knowing that only five motors are available to control all parts of the vehicle and arm, and that my partners design for the arm requires the use of three of those motors, I was left with two motors to both steer and propel the craft.
   
PROPULSION
One of those motors will be used to turn a single drive shaft, which will turn the propeller coming out the back. About midway down that drive shaft is placed a large gear, which turns another perpendicular gear that is on an axle that turns the back wheels. This means that a single motor is propelling the vehicle through the use of wheels on land, and a propeller on water.

TURNING    
The front wheels are going to be used for turning. Using a system similar to a rack and pinion type car steering set up. The axle will be turned utilizing a single motor placed vertically with the spindle facing down attached to a gear on the front axle. When this motor turns the gear the wheels will turn either direction depending on what the command is for. This system will turn the craft both on land and in water.
   
HULL DESIGN
The hull design had only a single reasonable solution, and it is a basic flat bottom boat shape, similar to the design used on a Louisiana airboat. This design allows the craft to move across the water most efficiently while still allowing the craft to have adequate interior space to house all of the propulsion components along with the room for the arm and all of the objects it picks up.