MIT spinout Coastal Assembly builds artificial reefs to restore shrinking beaches

Coastal Assembly, a startup spun out of MIT, restores beaches using artificial reefs made of custom concrete blocks. A 300-foot shoreline in the Maldives doubled in size over two years; the company raised $4.4 million and is expanding to Boston and Miami.

• Maldives beach grew 90 feet in 6 months and doubled in 2 years
• 54 concrete blocks installed roughly 150 feet offshore
• Startup raised $4.4 million this summer as a public benefit corporation
• AI analyzes satellite and ocean current data to plan reef layouts