OK. I've already spent all day on the computer so I'll make this fast. The submarine competition was pretty freakin' sweet. The subs had a couple of mission statements:
1) Have ability to drive forward/back/side to side on surface
2) Have ability to dive underwater... and have same control
3) Pick up 3 lb metal cube "payload" from bottom of pool and retrieve it

Here's a brief description of the 4 teams and their performance:
A) Seawolves

You can see the highly segmented design. Extremely complex - they used a pair of counter-rotating propellers to cancel out the roll torque. This team's design has two ballast tanks which can be pressurized with water or depressurized with reserve air. Basically it performs like it looks it will: it had great speed but didn't turn worth a crap. The also employed a really interesting payload recovery mechanism.

B) 20,000 M.E.'s Under the Sea

Performed essentially like a boat on the surface. The ballast tanks are either completely full or completely empty - so it either really floats or REALLY sinks. Overall the best driving performance, but it didn't have any of the cool features the other ones did.

C) Submarine 9

Interesting design: the ballast tank is a concentric cylinder around the sealed inner compartment which contains the important stuff: radios/motors/ballast pumps. Unfortunately - it entered the water only once for about 10 seconds. Long enough to flood the main component tank and short out the radios. Nice. They also didn't employ the trailing antennae method the other teams did - so they couldn't get any signal below about 4 ft. of water depth.

D) Sharkmouth (I don't know the real team name - but it's obvious why I call it that)


I think this team had the coolest design. Essentially symmetric front-to-rear, this model has naturally neutral buoyancy - so what drives it up and down are the twin vertical ducted fans in the nose and tail. It also has the propulsion motors on extended booms, so it really turns on a dime. Their payload retrieval mechanism is just a giant hook. After the payload is grabbed - they can blow reserve ballast in the nose & tail cones to offset the new weight addition and rise to the surface. Initially it had the best performance by far, but it turns out that having the propulsion so far out made it really unstable, so it was difficult to control. Overall, though - this design was best at all the control aspects: going/stopping, turning, and rising/falling in the water.

What about the payload? Well all the teams eventually had technical difficulties so they quit before getting that far - but it was still about an hour and a half of presentations/competition.

My senior design will be way cooler than this stuff..... but in general I'm pretty impressed with their efforts.