The world’s first sailing hydrofoil. The metal foil ladders on both sides and at the rear of “Monitor” function like airplane wings, lifting the boat out of the water as the wind increases pressure on the sails. At 800 pounds, “Monitor” can only rise out of the water with winds over 13 miles per hour.
“Monitor” has been clocked at more than 35 miles per hour fast for any sailboat.
All of Gordon Baker’s mechanical genius was not expended on military hydrofoil applications. About 1950 he was interested in using hydrofoils for sailing purposes, having built a three V-foil cat boat with an airplane foil configuration (two foils forward and one aft).
Speed ratios of over 1.5 times the real wind velocity were recorded. However, it had a tendency to “pitch pole” when running before the wind and would go into “irons” when coming about. These undesirable characteristics led Baker, with US Navy backing, to develop the MONITOR, a sloop with two ladder foils forward and a submerged foil aft. The forces of all the stays were fed into a mechanical computer.
Based on these inputs, the computer determined and then set, through a linkage system, the appropriate angle of attack on the aft foil for the wind in which the boat was sailing. This solved the problem of pitch-polling and made it possible to come about and stay on the foils. MONITOR first flew in 1955 and a pace boat clocked her at 25 knots.
In October of the following year she was paced at 30.4 knots. It was reported that MONITOR attained speed to true wind speed ratios of just over 2.0, and at times unofficial boat speed measurements close to 40 knots were observed. It is interesting to note that the U.S. Navy backing of MONITOR was motivated by its objective to learn more about the foil structural characteristics and construction methods used by Baker.
Check https://iscc.marinersmuseum.org/watercraft/monitor/ for more details
