Aluminum Weather-Resistant Structural Box

I need an aluminum box with one side open, designed as a structural component. The box must be weather-resistant, specifically for coastal use with high humidity and salt exposure. An engineer-stamped plan with strength measurements is required.

Requirements:
- Aluminum construction
- One side open design
- Weather resistance, particularly against humidity and salt
- Engineer-stamped plans
- Strength measurements

Ideal skills and experience:
- Mechanical engineering
- Experience with aluminum structural components
- Knowledge of weather-resistant design principles