You want the "Met and Hydrographic Messages" which are one type out of a very long list of message types.
AIS does not support this, but I believe Squiddio_pi does. Recently bouys were added, including Aton I believe. Yes, just checking Squiddio, under Preferences > View Tab in Cruising Aids you can check NDBC Bouy reports, NDBC Ship Reports and AIS markers.
This information is sent via your internet wifi
connection, as is all of squiddio's services. Nevertheless it can be very useful.
If you would like this added to Opencpn
AIS so that it is available via the two AIS channels, please make a Tracker feature request appropriately labeled and starting with "AIS ATON - ..." and get others to vote for it. (I will vote for it too)
Tracker is found at the top of the opencpn.org menu You must register.