Deb is Flo's sister sub. Designed in 2018 and manufactured shortly after, she is our newest sub that has made it past being a design on a computer. The Mechanical Subteam began assembling her during the 2019-2020 school year, but their efforts were put on hold once campus was evacuated due to COVID-19. Despite that, we are excited about how far Deb has come and can't wait until we get her moving through the water! Some sub highlights are listed below, but please reach out for our 2020 technical design report for more details!

Design Overview

If you look at our past 3 vehicles (Flo, Dory, and Crush), you may notice that they have similar main hull designs: generally restangular bodies with a curved acrylic dome. With Deb, we really wanted to step out of our comfort zone in terms of mechanical design and try something we had not done before. After brainstorming a number of general hull designs, we landed on a "plus"-shaped design. This seemed like a unique design choice that would still allow us to maintain a lot of familiar features from Flo, allowing some of Flo's electrical and software systems to be transferrable to Deb, eliminating a lot of unnecessary extra work for those subteams.


Deb's main body hulls are milled from the same aluminum alloy as Flo's hulls on a 5-axis CNC. The main unique feature of the hulls is their "plus"-sign shape. There is a large central cavity inside Deb for mounting the electronics package and external mounting space on the hulls for any additional mechanisms and manipulators. From Flo, we noticed that we did not have enough servo ports (she only has 3), so on Deb, we addressed this by doubling the number of servo ports to 6.

Upper Hull

The upper hull has mounting points for the handles (used to lift the sub manually and also act as latch points to lower the sub into the water at the TRANSDEC), the pressure gauge, pressure valve, gripper, hydrophones with transmitter, and ethernet mount and bulkhead. There is also a central rectangular acrylic plate that allows visualization of the electronics package for troubleshooting without having to depressurize and open the sub.

Novel design changes:

  • Hydrophones with transmitter: While Flo also has a set of 4 hydrophones, Deb has an additional transmitter. This fits with our competition strategy because we plan to have both Deb and Flo in the water at the same time. By giving Deb a transmitter, we enable her to communicate with Flo. Since we did not initially design Flo with the intention of having her communicate with another sub, she does not have a transmitter.

Lower Hull

The lower hull has mounting points for the thrusters, DVL, electronics package, battery pod system, and large camera dome.

Novel design changes:

  • Battery pods: The addition of multiports allow outside access to the batteries from the underbelly of the sub. This allows us to swap out the batteries without having to open the main hulls and moving around the electronics package.

Battery Pods

Deb was initially designed with 2 detachable battery pods. In the right image, the green boxes are the detachable pods, and the called out dark grey component is mounted inside the bottom hull to keep the batteries from moving around. This battery pod system will allow us to access the batteries without having to open the hulls. This reduces the amount of jostling to the internal electronics package and also can help to keep water out of our hulls. The battery pods hold pressure with a o-ring and latch system just like the main pressure seal of the hulls.

Camera Dome

Unlike Flo, who has 2 smaller camera domes which each house a single fixed camera (one wide angle lens and one narrow view lens), Deb has a single large camera dome that contains a camera mounted to a servo-driven gimbal. This will allow us to see a full field of vision, just like with the 2 fixed camera system in Flo.


Our general competition strategy is to have two subs in the water (Deb and Flo) and split the tasks evenly amongst them, in order to maximize our efficiency and be able to score the most points. We know that Flo is capable of consistently scoring markers, and we have also been working on a reliable torpedo launching mechanism for her. However, we do not have a very reliable gripper on Flo. For these reasons, the only manipulator we currently have planned for Deb is a belt-and-pulley driven gripper. This gripper will be used for any tasks that involve picking up a pool element and moving it to another location. However, we do also have free mounting space on Deb's external faces, in case we decide later on that we want to add more manipulators.