The (ransuersal stability results from a restoring moment, developed by the main hydrofoil when the craft heels sideways, and from the characteristics of the bow foils which, when fully submerged, produce a ten times greater lifting force than when they normally act as planing surfaces.

The longitudinal stability is a consequence of the pivoting
motion of the Aquavion about the points of contact
of the bow foils with the water surface.
Now suppose the hull is brought out of its normal position,
for instance, leaning backwards, then the angle
of incidence of the mainfoil is increased, which means
the angle of the submerged area of the foil is also
increased. This results in the hydrofoil being lifted
and therefore returning to its original horizontal position.

The directional stability is ensured by the fact that
'both the main hydrofoil and the stabilizer are
situated aft of the centre of gravity.

The stability in turns'. An important quality of
the Aquavion system is that an Aquavion heels inwards
when turning. This is due to the dihedral shape
of the main hydrofoil, which is nearly semicircular
in front elevation. Since an Aquavion will side slip away
from the centre of the turn (though far less than
other craft), the effective incidence of the outward part
of the foil is increased, and that of the inward
part is decreased.
Consequently the lift forces on the outward and inward
parts of the main hydrofoil respectively increase
and decrease, which makes the craft bank inwards.

Oscillations about the longitudinal axis of an Aquavion
are firmly damped out by the bow foils
and also by the struts of the main foil and aft-stabilizer.

Oscillations around the lateral axis are damped by
the aft-stabilizer, which has been specially designed
and calculated for this purpose.

These damping actions prevent the Aquavion from
oscillating in its natural frequencies, and so its dynamic
stability is guaranteed on every possible
wave-pattern, at all speeds and in any direction
relative to the waves.

In consequence of the tact that the stability and
comfort of the Aquavion are automatically ensured
under all conditions, there is no reason to equip it with
adjustable foils, and thus the possibilities of human
error, or mechanical defects are eliminated.

Experience with Aquavion hydrofoils in different lengths
of waves has shown them to be very
comfortable because of their outstanding stability.