NAV 44/9
They should also be joined by common
philosophy with amendments to COLREGs for HSC, if such
amendments are to be developed.
2.1.2 According to the concept of a WIG
Craft Code (DE 41/16) WIG Craft Is a vessel, which is capable
to fly, instead of plane, capable to float. It is classified
as a high-speed craft (HSC) on a dynamic air cushion, the
main operational mode of which is a flight at very small
altitude with use of reaction to an air-wing (wings) of air,
reflected from an earth surface, that is with use of a
"surface effect". By ability of operation outside
of a "surface effect" action altitude the WIG Craft
are divided to three types:
.1 Type A:a craft, which is not
capable to operate without the surface effect action,
.2 Type B: a craft, which is
capable to increase its altitude for a short-term and on
a limited magnitude outside influence of surface effect
in order to fly over a ship, an obstacle or for other
purposes. The maximum height of such an "fly
over" should be less than the minimum safe altitude
of an aircraft prescribed by ICAO.
.3 Type C: a craft, which is
capable to come off from the surface effect action for a
long time and to rise on altitude exceeding the minimal
safe altitude for an aircraft prescribed by ICAO.
2.1.3 As distinct from usual and
high-speed displacement vessels and also from
non-displacement HSC, WIG Craft have not I or 3, but seven
operational modes, being subject to consideration in relation
to a COLREGs. In a WIG Craft Code (DE 41/16) they are defined
as follows:
.1 "Displacement mode"
- means the regime, whether at rest or In motion, where
the weight of the craft is fully or predominantly
supported by hydrostatic forces.
Note: fully corresponds to
displacement mode of a HSC (see paragraph 1.4. 18 of
the HSC Code);
.2 "Skimming mode" -
denotes a mode of normal operation of a craft on a water
surface when the craft weight is supported essentially or
mainly by non-hydrostatic forces.
Note: same as non-displacement mode
of HSC (see paragraph 1.4.32 of the HSC Code). In
this mode the connection of a non-displacement HSC
with water can be limited essentially, the
characteristics of manoeuvrability. can considerably
differ from other vessels, and the direction of a
movement cannot coincide with direction to a vessel
bow. According to a COLREGs (Rule 23b), in this mode
the air-cushion vessel shall exhibit an additional
all-round flashing yellow light. This light does not
impose any special requirements and is intended only
for identification of a vessel.
.3 "Transitional mode"
- means the regime between displacement and skimming
modes.
Note: same as a transitional mode of
HSC (see paragraph 1.4.47 of the HSC Code), when it
exhibits lights for a power-driven vessel underway.
.4 "Surface effect
mode" (or "Flaring mode") - is the main
operational mode of flying a craft near to a free water
surface or to other supporting surface in a range of
altitudes of action the "surface effect".
Note: In this mode the contact of a
ship hull with a water is fully absent.
I:/NAV/44/9.WPD
