<s>
Mini-automatic	B-Algorithm
radar	I-Algorithm
plotting	I-Algorithm
aid	I-Algorithm
(	O
or	O
MARPA	O
)	O
is	O
a	O
maritime	O
radar	B-Application
feature	O
for	O
target	O
tracking	O
and	O
collision	O
avoidance	O
.	O
</s>
<s>
MARPA	O
is	O
a	O
more	O
basic	O
form	O
of	O
ARPA	B-Algorithm
(	O
automatic	B-Algorithm
radar	I-Algorithm
plotting	I-Algorithm
aid	I-Algorithm
)	O
.	O
</s>
<s>
The	O
relative	O
motion	O
of	O
a	O
target	O
can	O
be	O
seen	O
with	O
Relative	O
vectors	O
,	O
these	O
just	O
show	O
the	O
future	O
position	O
of	O
the	O
target	O
on	O
the	O
Radar	B-Application
screen	O
per	O
Vector	O
Duration	O
,	O
again	O
usually	O
6	O
or	O
3	O
minutes	O
depending	O
on	O
range	O
in	O
use	O
.	O
</s>
<s>
Most	O
colour	O
Radar	B-Application
displays	O
can	O
show	O
both	O
TV	O
and	O
RV	O
simultaneously	O
.	O
</s>
<s>
It	O
is	O
essential	O
that	O
users	O
of	O
MARPA	O
not	O
confused	O
them	O
,	O
especially	O
on	O
Radars	B-Application
that	O
cannot	O
display	O
.	O
</s>
<s>
Relative	O
vectors	O
provide	O
,	O
at	O
a	O
glance	O
,	O
information	O
about	O
which	O
vessels	O
pose	O
a	O
collision	O
risk	O
;	O
a	O
RV	O
pointing	O
at	O
the	O
centre	O
of	O
the	O
Radar	B-Application
screen	O
indicates	O
a	O
risk	O
of	O
collision	O
.	O
</s>
<s>
MARPA	O
(	O
mini	O
or	O
manual	O
ARPA	B-Algorithm
,	O
depending	O
on	O
which	O
company	O
you	O
talk	O
to	O
)	O
is	O
the	O
dominant	O
one	O
.	O
</s>
<s>
MARPA	O
,	O
ATA	O
(	O
automatic	O
tracking	O
aid	O
)	O
,	O
and	O
ARP	O
(	O
automatic	O
radar	B-Application
plotting	O
)	O
all	O
function	O
similarly	O
to	O
ARPA	B-Algorithm
.	O
</s>
<s>
The	O
major	O
difference	O
of	O
this	O
Radar	B-Application
plotting	O
aids	O
may	O
not	O
be	O
fully	O
equivalent	O
to	O
all	O
ARPA	B-Algorithm
performance	O
standard	O
of	O
IMO	O
approved	O
type	O
which	O
is	O
a	O
mandatory	O
requirement	O
for	O
large	O
ocean-going	O
ships	O
.	O
</s>
