A top speed of  was achieved, with the hydrofoil exhibiting rapid acceleration, good stability, and steering, along with the ability to take waves without difficulty. In 1913, Dr. Bell hired Walter Pinaud, a Sydney yacht designer and builder as well as the proprietor of Pinaud's Yacht Yard in Westmount, Nova Scotia, to work on the pontoons of the HD-4. Pinaud soon took over the boatyard at Bell Laboratories on Beinn Bhreagh, Bell's estate near Baddeck, Nova Scotia.
A top speed of  was achieved, with the hydrofoil exhibiting rapid acceleration, good stability, and steering, along with the ability to navigate waves without difficulty. In 1913, Dr. Bell hired Walter Pinaud, a Sydney yacht designer and builder as well as the proprietor of Pinaud's Yacht Yard in Westmount, Nova Scotia, to work on the pontoons of the HD-4. Pinaud soon took over the boatyard at Bell Laboratories on Beinn Bhreagh, Bell's estate near Baddeck, Nova Scotia.