Page 52 - Collision Avoidance Rules Guide

Small craji and ice
Minor targets such as small coastal vessels and trawlers should
normally be detected at distances greater than 6 miles, provided the
set is properly adjusted, but yachts, open boats and other small craft,
especially boats of fibreglass construction, usually give poor echoes
and may not be detected in time to take effective avoiding action.
The fitting of an efficient radar reflector is likely to considerably
increase the probability of being detected and may double the range
of detection for a small vessel.
The Safety of Life at Sea Convention (SOLAS) requires all ships
of less than 150 gross tons to be fitted, if practicable, with a radar
reflector or other means, to enable detection by radar at both 9 and
3 GHz. The reflector should be of an approved type complying with
minimum performance standards, preferably mounted at a minimum
height of 4 m above water level.
The following two collisions, which occurred off the coasts of the
United States, illustrate the danger of placing too much reliance on
radar in areas where small craft may be encountered. Both of the
fishing vessels referred to sank with resulting loss of life.
In September 1959, the ss Momzacpine was approaching the
Straits of Juan de Fuca in visibility estimated at between 500 and
1,000 yards. Full speed, of approximately 11 knots, was being main-
tained, but the engines were on stand-by. The radar was on the 8 mile
range and appeared to be working satisfactorily. When a fog signal
was heard ahead the engines were immediately stopped. The master
1
checked the radar and found no targets. Approximately 17 minutes
later the look-out reported sighting a vessel 1,000 feet ahead, fine
on the starboard bow. This later proved to be the Jane, a 49 foot,
wood hull fishing vessel. Although the engines of the Momzacpine
were immediately put full astern, this was not sufficient to prevent
collision.
In April 1961, the South African Pioneer was on a voyage from
Charleston, South Carolina to New York. In visibility of approxi-
1
mately 11 miles the engines were placed on stand-by, resulting in a
speed of approximately 10 knots. The radar was on the 8 mile range,
and sea clutter was observed to extend approximately 3 miles out
from the centre of the display. No targets had been observed by radar,
but a light was sighted 10" on the starboard bow. This later proved to
have been the sidelight of the Powhatan, a 78 foot wood hull fishing

33