Another important component of the tank is its steel bolt connectors. Because the tank is made and shipped in pieces, there has to be some way to fasten everything together. This seemingly simple requirement is complicated by the fact that the inside of the tank needs to be smooth, which means the connector heads have to be countersunk so they are flush with the inside.

After fabrication, the tank pieces are transported to remote sites. There, workers assemble the pieces on skids, then slide the completed tank into the sea. Water is pumped in, and the tank sinks until its upper lip rides about two feet above the ocean.

Thanks to hard work by all of the partners on the project, the tank is a success: Wilton says that the observed and measured physical properties of the latest tank version match predictions in terms of deflection, buoyancy and other parameters. AgriMarine exported two tanks to Norway in early 2015. Other tanks will soon be deployed elsewhere because, says Wilton, economics favor this type of fish farming. “The fish output is significantly higher,” he says. “It definitely is worth it.”