"Doug" wrote in
.net:

About a month ago Group Portland (MSO Portland, OR) started using
Sector Portland. This went on for a week and then they went back to
Group Portland. I believe they jumped the gun on the switchover to the
Sector call sign. Doug K7ABX

I think this paragraph from the CAMSLANT webpage tells a lot why open calls
are not being answered on HF-SSB at USCG coast stations....

"•Guarding specified international distress frequencies, (High Frequency
Digital Selective Calling) responding to emergency signals and requests for
medical advice."

If you're screaming your head off, waist-deep in seawater, on your Icom HF
radio and THEY are waiting for a DSC call without the speaker making all
those nice, old HF noises.........you ain't gonna git saved.

http://www.uscg.mil/lantarea/camslant/station.htm

"HF DIGITAL SELECTIVE CALLING
Portsmouth/NMN, Boston/NMF, Miami/NMA, New Orleans/NMG, Pt. Reyes/NMC,
Honolulu HI/NMO, Kodiak AK/NOJ

2187.5 kHz Coast Guard will normally respond to DSC test calls if
acknowledgment is requested. Reports of uncancelled or unacknowledged
inadvertently transmitted distress calls will be forwarded to the Federal
Communications Commission.
4207.5
6312
8414.5
12577
16804.5

Note: For radiotelex and digital selective calling,
frequencies listed are assigned. Carrier frequency is
located 1700Hz below the assigned frequency."

http://www.navcen.uscg.gov/marcomms/cgcomms/call.htm