Danu

built in the open

Danu

A homemade autonomous submarine — built from scratch to explore Lake Michigan's shipwrecks on her own, and one day, the oceans.

Follow the build — the wins, the floods, the firsts.

Know someone who'd love this? Spread the word — send it to the friends and family who'd find Danu right up their alley.

Dive in

the Dream

Fascinated by the water. A little terrified of it.

For as long as I can remember, I've been pulled toward the water — and a little afraid of it. As a kid I'd watch Jacques Cousteau's Nat Geo specials, mesmerized by a world most people never get to see. I love history, too, and it still amazes me that the seas hold so much of it — stories and ships and lives that were never recovered.

I've tried scuba a handful of times, but diving genuinely scares me. The same immense power and unknown that makes the ocean beautiful is the part that terrifies me. An autonomous submarine is how I get around that — she goes where I can't, and brings the view back to me. And for the first time, it actually feels within reach: with tools like the AI from Anthropic, OpenAI, and Google, someone without a marine-engineering degree can design and build a machine that does exactly what he imagines. As much as anything, this is an engineering challenge — and I'm here for it.

The dream itself is specific, even if I can't fully explain it: a sub that explores on her own, surfaces to get her bearings and send back what she's found, then slips under to keep going. Discovery — especially of something new — going where people haven't, and taking everyone along for the same view I get.

It's already worth it — and I haven't even put the first pieces together.

I'm building it with my daughter, Aarushi. She starts high school this fall, she wants to be an aeronautical engineer at NASA, and she's a die-hard Mark Rober fan. Her time will ebb and flow as school and life pull at her — but any chance to make something meaningful together is a blessing, and this is a multi-year journey we get to take side by side.

I don't know where it ends — success, failure, or some direction I can't see yet. No matter what, it's a journey. One day I'd love a whole fleet of undersea rovers out there mapping, recording, and discovering across the oceans. To be alive at a moment when that's even thinkable feels unbelievable to me.

That's why I'm doing it in the open. I love to teach, and here I get to share what I'm learning as I learn it — the how, the mistakes, the floods and the failures, and the wins. Building in a vacuum was never the point. If watching us figure this out shows even one person that you don't need permission or a PhD to build something audacious, that's the whole thing.

Follow the build →See what we're building ↗

the Name

Danu — goddess of the celestial waters

In Hindu mythology, Danu is the primordial goddess of the celestial waters — the flowing source from which life and the rivers spring. It felt like the right name for a vessel meant to move quietly through deep water, learning as she goes.

the Plan

From the workbench to the wrecks

✓
2026
Design & spec
done

Lock the whole vehicle on paper — hull, propulsion, power, autonomy, recovery.

✓
2026
Build the bench bot
done

Order the first parts and bring the brains to life on the workbench.

Fall 2026
Fully wired battery packs with all wired sensors
current

3 Battery Packs - 4 banks in each pack - 16 batteries in each bank = 192 Batteries in Total! Each Pack sealed in it's own water tight tube with power and sensor wires traveling between tubes. Sensors: BMS (Battery Management System), Voltage Sensor, Current Sensor, Temperature-Humidity-Pressure Sensor, Cell Temperature, Cell Voltage Checker ***Power is key!!!

Winter 2026
From bench to vehicle
upcoming

The trays come together and the tubes get filled. This is where a bench full of boards stops being a prototype and starts being a submarine that can power itself.

Winter 2026
Sealed, shaped and balanced
upcoming

Twenty-five liters of syntactic foam shaped by hand into a hull, every seal proven dry, and the buoyancy spreadsheet finally weighed against real water.

2026
Pool & reservoir tests
upcoming

First water: watertightness, ballast & trim, then autonomy in a reservoir.

2027
Lake Michigan wrecks
upcoming

Real missions — transit out, find a wreck, film it, come home.

someday
The open ocean
upcoming

The dream: a vehicle that crosses open water on its own.

Right now
Fully wired battery packs with all wired sensors
  • •Weld 30mm nickel strips to +/- terminals of each battery
  • •Create banks of 16 batteries with nickel strips welded to single nickel (or soldered to copper for top and bottom pack) plate.
  • •Run all sensor wires through pack in-between banks and cells as required. 10AWG from Top and Bottom Pack plates. 22 AWG sensor wires from each nickel plate. Place heat sensor per bank with wire run.

the Build

Every part, out in the open

The full build — every system, its parts, and where each one stands, plus the build log and expeditions.

Open the build dashboard →

the Log

From the ship's log

The latest entry — design & build decisions, recorded as we go.

The first bank

One of the three battery packs is finished. 64 cells, 14.28 volts across the whole thing, and all four groups reading exactly 3.57 . . . which is about the best first-pack result I could have hoped for. Four groups sitting at the same voltage means every parallel connection is doing its job and…

Read the full log →

the Team

Amar & Aarushi

Amar & Aarushi

Danu is a father–daughter project — built at home, in the open, learning as we go.

About

Built in the open. Follow along on X: @danuthesub (the sub's own voice) and @danutheauv (the engineering log).