My comment about private was with PRIVATE in quotes - thus "Private" frequencies. Obviously, no frequency is private, but using a non-standard AIS frequency would keep it off the internet (for a while) , but would permit various USCG units to see each other whereabouts.
Well, here's my take on it,
"private" isn't the term they'd use. They'd use "secure". Simply running on a different frequency wouldn't qualify as 'secure' in USCG terms. It's only useful until someone figures out what they are doing and then uses available software and an SDR to get their location. Then it's not longer secure, or private. Kind of like hiding the key for your front door under the mat.
I was theorizing, that a simple system for smaller patrol boats coordinating with larger cutters, using an AIS type system, that displays on the various chart display, would be VERY handy, and easy to implement. it could even be encrypted, if warranted.
Radar would meet that need.
It's been a long time since I did this stuff, and back then AIS wasn't a thing. Heck, GPS was 'new' to us. We still used LORAN-C as our primary navigation means.
The few times we sent a small boat out over the horizon, they carried a VHF radio and a hand held LORAN-C receiver. On the bridge, they kept track on the radar.
I'm sure a
private secure AIS type system would be great, and I don't know for sure that they do not have such a thing. Just never heard of it, but there's a lot of stuff I probably haven't heard of.
My thoughts are that the small patrol boats want something simple and cheap, and not the sophisticated systems that a cutter would require.
Well, they have radar and lots of communications tools. Maybe they have such a thing, maybe they don't. If they do, it's going to be secure. They have encryption on their radios and if they are going to shut off their standard AIS system to do sneaky stuff, they'd be smart enough to encrypt whatever secret AIS system they were running.
Or another way to phrase the question: - If I see a USCG small patrol boat with my eyes zipping around a harbor at 20 knots, and it does not show up on on AIS, what do you think they are using? I doubt IFF on a small 2 to 4 person boat. I doubt they were running RF silent for geolocate data transmissions. USCG District HQ and coordinating cutters nearby would want to know where they are located. I suspect voice position reported would NOT be adequate, if the mission is important enough to turn off the standard AIS TX.
Thanks for the insights and thoughts on the matter.
I don't know. What I do think is that you are confusing the roles of the boats you see in the harbor. The small boat stations primary role is search and rescue. Usually at least one person on the crew of that boat has been through the appropriate boarding team schools and they have law enforcement authority. But their job is not to chase down drug runners. The USCG has specific teams and assets for that. Those specific assets have different capabilities than what you'd see running around the harbor. The aircraft have satellite capability, as do the larger ships. The smaller boats used by the maritime law enforcement teams probably have similar stuff. The satellite antennas used is very distinctive, and I've never seen one on top of the standard RBM's and similar boats used at the station level.
So, different roles. Shutting off the AIS is an easy solution. While you might think they are running "blind" with it off, they usually aren't. District level HQ wouldn't be live tracking individual small boats like that. That would be handled at the station level, and checking in periodically by voice would be sufficient.
If they do have some secret squirrel AIS system, I'd be a dollar its encrypted. Sort of pointless without that.
If you find something different, let us know.
