The "Ironclad Board" consisted of Commodores Joseph Smith and Hiram Paulding, Commander Charles H. Davis, and Assistant Secretary of the Navy Gustavus Fox.
The board received seventeen proposals of different form, practicality, and degree of detail, ranging from William Norris's ninety-ton steam gunboat to Edward S. Renwick's 6,520-ton giant.
Even with a conventional sailing rig, the proposal was bizarre, and the board required Bushnell to guarantee the ship's ability to float and its stability.
Ericsson's design had the shallowest draft and shortest estimated construction time, but against it were its extremely low freeboard, turret-mounted guns, and total reliance on steam power.
Board members saw what the Union navy needed instantly—"vessels invulnerable to shot, of light draught of water"—but other factors clearly affected their deliberations.