Ian Waugh - A Mariner\'s Guide to Marine Communications

transmit for up to eight hours, provided that the battery is still in date

and the SART has passed its regular monthly tests (see later).

SART detection by marine radar

IMO Guidance (SN/Circ. 197) for the operation of marine radar

for SART detection suggests:

Use the 6nm or 12nm scale (to help distinguish the line of SART

response dots from other targets).

Use medium bandwidth on the radar (this may have to be selected

manually when on the 6nm/12nm range scale.

Consider de-tuning the radar to reduce clutter - but beware of losing

other wanted navigational/anti-collision information. (Return to

normal tuning as soon as possible).

Set gain to normal for long range detection (light background noise

sparkle visible).

• Set anti-clutter sea control to minimum (but beware of losing other
  targets).


• Set anti-clutter rain control to normal.
  Note that, in clutter conditions, the first few dots of the SART
  response may not show on your radar - in which case the SART
  position may be estimated by measuring g·5nm from the furthest dot
  back towards your own vessel.

~~A

f ....

r

f········ \ _"'

I:" •...

\:" -~ ~ ., ~

~ ...

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Figure 70.4

SART transmissions on an approaching vessel's radar screen

When the approaching vessel first detects the SART, the SART
transmission will appear as a line of (approximately) 12 dots on the radar
screen - along the line of bearing of the SART (figure lO.4A). The dot
nearest to the approaching vessel's position is the location of the SART.

When the vessel approaches to within about one mile of the SART
location, the dots will change to arcs (B) and, when closing the SART
position, to concentric circles (C). It is suggested that vessels approaching

MARINE COMMUNICATIONS 191