Mechanical Design:
This year's design reflects the many lessons learned from the previous models. While the overall design remains similar, this year's model is an effort to overcome the limitations of earlier approaches to the competition. All design and fabrication of the boat was done in-house with the exception of the two pontoons. With the change in venue from a relatively calm pool to a small lake the philosophy we took to this design was to make things stronger and more resilient, while also increasing the performance of our mechanical systems. Our design is faster and more agile than it has been in previous years. Ease of assembly and adaptability were taken into consideration much more so than they were in the past. Both mechanical and electrical components can be easily removed, changed, and reorganized without making major alterations to the boat.

Pontoons
The pontoons used on this year's boat come from the Venture Outdoors, Echo Perma 4.5' Kick Boat Model and are made of rigid, puncture resistant plastic. Each Pontoon 4.5'' long and has a diameter of 11". This displacement allows us to sit high enough on the water to allow a good view of the course without having too high a center of gravity. The pontoons are spaced a foot apart to allow for the computer case to rest vertically between the two. This design keeps our center of gravity low and allows for the maximum utilization of the space above the pontoons, and out of the water. The boat frame is attached to each pontoon both in front and in back. The frame is strapped to the top of each pontoon with Velcro belts. Gel Pads are placed between each strap and the pontoon to reduce vibration from the motors.

Frame
The frame is constructed of 1" boxed aluminum poles rived together using 1'' angle aluminum and 5/32'' rivets. Aluminum was chosen for its light weight and non magnetic properties. The Boxed poles make for the easy mounting of sensors and motors. The frame disassembles into two pieces, the top-frame where the sensors and computer case are mounted and the bottom-frame where the motors are mounted, to allow for work on the motors and easier transportation of the boat. A 12.5'' tower extends above the top-frame and acts as a sensor mount. A front bumper made of 1/2" c-channel aluminum extends from the middle of the top-frame to avoid buoys and other obstacles from becoming caught between the pontoons. At the back corners of the top-frame are eye screws to facilitate the thrust test.

Propulsion
SS Boatname uses five Seabotix SBT150 brushed thrusters. All are mounted below the pontoons on a flat 1'' bar that has been reinforced with a 1" L-shaped bar. This bar is positioned in the middle of the boat for maximum turning ability. Four are mounted axially to provide speed forward and backward while the fifth motor is mounted laterally to allow the boat to strafe sideways without changing heading or forward velocity.

Computer Case
Our computer case is a modified Hardig Storm Case which rests vertically between the two pontoons. The case is strapped to the frame with a ratcheting tie-down. Within the case are the boats computer, circuit board, motor controllers, micro-controllers and batteries. Screw down, Bulgin water-proof connectors are recessed into the front of the case and act as our breakaways to the boats motors and sensors. This allows for easy removal of the electrical components and computer from the boat for transportation and maintenance. The circuit boards are attached a Plexiglas sheet which is attached to the inside lid of the case using stand-offs. The computer is attached to an aluminum plate on the bottom of the case. This aluminum plate acts both as a mount for the computer and a heat sink. Airflow through the case is directed over the computer through a Plexiglas baffling system. Computer blower fans are used to make a high pressure chamber on one side of the case. This higher pressure chamber leads to the outflow air vent of the case. On the other end of the case is the inflow air vent. Over each external vent there is a Plexiglas "sink trap" which uses gravity to separate air coming into the case from any water spray that may have splashed on the computer case.

Sensors
Our boat uses three sensors to orient itself on the course, a wide-view format DV camera, a Garmin GPS and a digital compass. Our camera is mounted inside a waterproof, aluminum camera case located on the 12.5'' tower. This camera case is hooded and painted matte black to reduce glare on the lens of the camera. Bolted to the top of the camera case is the GPS. This placement was chosen because it is the tallest point on the boat and therefore will always have a clear view of the sky. The boats compass is mounted inside of a waterproof case and placed at the front right corner of the top-frame where it connects to the right pontoon. This position was chosen to isolate the compass from the electromagnetic processes of the computer.

Water Cannon
This year's water cannon is more powerful and maneuverable than its predecessor. It uses of a windshield wiper fluid pump mounted below the water line on the bottom-frame. Tubing is run from the pump to a second camera at the rear left corner of the top-frame. The cameras waterproof case is mounted pan and tilt servo kit which can move independently of the boats direction. This orientation allows the boat to fire broadside at targets while continuing its path to other parts of the course. This camera will also be used to orient the boat with the rescue ring during the Rescue Retrieval portion of the competition.

Rescue Retrieval Arm
The arm for retrieving the life ring is made of 1/2" angle aluminum with a curved section at its end. When not in use it lays draped over the top frame. At the rear middle of the top-frame is the arms motor about which it rotates to extend beyond the rear of the boat when retrieving the life ring. Strung along the curved end of the hook is a steel cable connected to a touch sensor that allows the program to recognize when the life ring is secured to be towed.