Engineering Class Boat Project: Jayden's Boat! 4/15/25

Our sophomore-year engineering class challenged each team to design and build a small watercraft that balances stability, buoyancy, and manufacturability. Working alongside three classmates, I led the CAD modeling and simulation efforts, using Fusion 360 to bring our ideas to life.

We began with a deceptively simple goal: create a boat that floats level under a 800 g load while minimizing overall volume. Beyond buoyancy, we weighed factors like ease of assembly, material costs, and aesthetics. From the start, we aimed for a hull that would be lightweight yet strong, easy to fabricate with common shop tools, and hydrodynamically stable in calm water.

Before launching into CAD, we sketched wildly different hull shapes on paper. Some teammates favored a V-shaped keel to slice through water; others preferred a wide flat bottom for maximum stability. After debating pros and cons, we settled on a hybrid design: a flat bottom for predictable buoyancy, slightly flared sides to deflect small waves, and a narrow bow to reduce drag.

With our concept approved, I opened Fusion 360 and translated those sketches into a precise 3D model. I started by drawing a 2D hull profile, then revolved it around the centerline to create a solid form. Next came splitting the body to carve out the interior buoyancy chamber, adding fillets to smooth edges for better flow, and using the Appearance tool to apply realistic materials and finishes.

To verify our design, we ran both buoyancy and finite element stress analyses. The buoyancy test calculated displaced volume against submerged depth to confirm our float height, and the stress study checked wall thickness under internal pressure so we wouldn’t risk failure. Simulation results prompted a few tweaks: we thickened the stern near mounting points and added transverse ribs to distribute weight evenly.

For materials, we chose 4 mm high-density polyethylene sheets because they’re budget-friendly, impact resistant, and weldable with a standard plastic hot-air welder. Our build plan included cutting hull panels on a CNC router, heat-bending bow sections for a rounded shape, butt-welding seams with a slotted clamp jig, and installing internal ribs and deck support.

This project drove home several key lessons: running simulations early saves hours of physical rework, small changes in wall thickness can dramatically affect buoyancy, collaborative CAD environments prevent version-control headaches, and hands-on fabrication often reveals tolerances you can’t predict in a model.

Now that our CAD model is validated, we’re gearing up for shop build. We’ll procure HDPE stock and test a scrap-piece weld, generate detailed cut lists and jigs from our Fusion 360 drawings, and plan a live pool test day to measure trim, ride height, and overall stability. I’m proud of how our team melded creativity, analysis, and fabrication skills stay tuned for photos and performance data once we launch our boat in the campus pond!