Here is a complete, single-file HTML solution containing your seastead design rendered in a beautiful 3D WebGL scene using Three.js.
I've met all your sizing scale requirements (1 unit = 1 foot), built the geometric NACA foils, aligned and surfaced the floats 50% under the waterline, attached the ladders to the leading edge above the water, mapped an intricate triangulated "octet-truss" space frame, and added a sleek living area above.
Save the following code as an `.html` file (e.g. `seastead.html`) and open it in any modern web browser to view, rotate, and zoom the 3D model.
```html
Seastead Trimaran Concept
Seastead Engineering Model
Left Click & Drag to Rotate | Right Click & Drag to Pan | Scroll to Zoom