We built a simple frame that hangs in the boat from the gunnels or top edge of the hull. We then welded on angle and flat bar to form a template of the hull that was used to transfer the measurements onto the steel. The flat bar makes a better template because it can be cut and bent to conform better to the hull plate.
Pipes are welded in place to spread the hull open.
Bulkhead template frame resting in the hull and angle iron tacked to measure were the cargo forward cargo hold bulkhead will be installed.
Transferring template points to the steel
A better bulkhead template that uses flat bars.
Bulkheads looking aft
Bulkheads looking forward