Im not too sure actually if those talkgroups in message 1183 are used anymore? Has anyone heard them lately? Last few years Coast guard station Saginaw river in Essexville that used to have a talkgroup on the database, but have been on their Rescue 21 frequencies for at least a few years.
These are P25 with a NAC 293 tone.
I read elsewhere on the forums that the Coast Guard uses these nationwide.
United States Coast Guard - The RadioReference Wiki
You'll find station Saginaw River is on AG 102 with the boats encrypted, Station Tawas on AG 101 encryption is in similar usage.
412.925 I have heard being used for HELO ops but are often encrypted.
Far as Coast guard jets I have heard them a few times before. They contact station Saginaw river and ask them to take their radio guard which is usually 157.050 or 157.150