The following was picked off the packet BBS of N2GJJ.  Please add comments,
additions through the SWL conference (type j;swl from the main menu).  SYSOP.

  Msg# TR  Size Read To     From   @ BBS   Date  Time
   138 BN  3845    5 ALL    WB3JOE N2GJJ  870113 0922
 Title: Coast Guard Frequencys
 
At WB3JOE:   205 From WB3JOE Rcvd 870113/1208, Sent 870113/1413 UTC

   The following is adapted from data
received by Jay N3CHG and the resp-
onse given by Dale KB1AJ regarding the
use and frequencies used at Coast 
Guard stn NMN Portsmouth Va.   Both
of these gentlemen are acknowledged
with thanks...
***All freqs Khz, times are GMT
CW HF safety and Liason traffic:
Working          series guarded:
8465             8363.2-8363.4
12718.5          8364-8364.8
16976            8362.4-8363.2
                 12544.8-12546
                 12546-12547.2
                 12543.6-12544.8
                 16726.4-16728
                 16728-16729.6
                 16724.8-16726.4
All frequencies are guarded 24 hrs
a day by scanning receivers except
the 16 Mhz channels which are 
guarded from 1100-2300 daily.
Voice (USB) safety and Liason Tfc:
***Note all frequencies are carrier
frequencies...add appropiate offset
as required*****
Coast       Ship      Times guarded
4428.7      4134.3    2300-1100
6506.4      6200      0000-2400
8765.4      8241.5    0000-2400
13113.2     12342.4   1100-2300
17307.3     16534.4   on request only
General CW broadcast and notices:
8090.0-continuously
12135.0-continuosly
16180-continuously
20225-1200-0000
Time        Traffic
0200-0600   CW training-6-20 WPM
0600-0800   Red Sea, Meditteranean,
            Black sea, Arctic and 
            Western Atlantic wind and
            sea warnings
0800-0900   Hydrolant, Ice warnings
            and special warnings
1000-1300   Hurricane and other wx
            warnings for Western 
            Atlantic Caribbean and
            Gulf of Mexico
1500-1600   Navarea IV, Ice and special
            warnings
1600-1700   Hydrolant, Ice and special
            warnings
1700-1800   Repeat of 1000 broadcast
2000-2100   Tropical Wx summary and
            Gulf stream locations
2100-2200   same as 1500 broadcast
2200-0100   same as 1000 broadcast
Voice (USB) broadcast and working 
Frequencies:
Wx broadcasts at 0400 0530 1000 1130
1600 1730 2200 and 2330 
Shore       Ship         Time
4428.7      4134.3       2300-1100
6506.4      6200         24 hours
8765.4      8241.5       24 hours
13113.2     12342.4      1100-2300
17307.3     16534.4      on request
CW working frequencies for mariners:
NMN         ship range      time
8465       8362.4-8364.8    24 hours
12718.5    12543.6-12547.2  24 hours
16976      16724.8-16729.6  1100-2300
Offshore and High Seas forecasts:
GMT  Fcst  A  B  C  D  E
0400 01    x  x  x
0530 h     x  x  x
1000 02    x  x  x
1130 h        x  x  x
1600 02,g     x  x  x
1730 h           x  x  x
2200 02,g     x  x  x
2330 h        x  x  x
Fcst codes:
01  Offshore forecast for West Cen
    North Atlantic, SW N Atlantic
    Caribbean and Gulf of Mexico
02  same as 01 including New England
h   High seas Forecastfor N. Atlantic
    West of 35 degrees West, Caribbean
    and Gulf of Mexico
g   Gulf stream location
Freqs:
A 4428.7
B 6506.4
C 8765.4
D 13113.2
E 17307.3
  According to the sample QSL letter,
the receiver site is located in 
Chesapeake, Va. with the transmitter
site located in Pungo, Va.  They use
Collins 651s-1a receivers, Collins
HF8090 10 kw HF transmitters and 
FRT89 1.5 kw MF transmitters.  The
receive antenna consists of Vertical
and horizontal Omni directional 
rotatable Log Periodic and Herms Loop
arrays.  The transmit antenna system
consists of Vertical and Horizontal
Omni Directional fixed and Rotatable
Log Periodic arrays and MF Transmit
towers.
  D R O O L .....
Hope this info is of help to the 
mariners out there...by the way KB1AJ
is a RM1 at that station so this info
is bound to be accurate...any errors
that have crept into this are entirely
mine  73s.