In which format are encoded AIS message strings available?

A description of the offered format for encoded AIS messages

The National Marine Electronics Association (NMEA) controls the standard for encoded AIS messages. The Spire Sense TCP Feed sends encoded AIS messages in the NMEA 0183 v4.0 format with a timestamp TAG block as a prefix.

Some example messages from the Spire Sense TCP Feed are below:

\c:1503079500*55\!AIVDM,1,1,,B,C6:b0Kh09b3t1K4ChsS2FK008NL>`2CT@2N000000000S4h8S400,0*50

\c:1503079517*53\!AIVDM,1,1,,B,16:Vk1h00g8O=vRBDhNp0nKp0000,0*40

\c:1503079517*53\!AIVDM,1,1,,B,18155hh00u0DEU`N1F@Bg22R06@D,0*60

\c:1503079517*53\!AIVDM,1,1,,A,83aGFQ@j2ddtM<M>H1b@g?b`7mL0,0*55

\c:1503079517*53\!AIVDM,2,1,9,A,53m@FJ400000hT5<0008E8q@TpF000000000000T2P3425rg0:53kThQDQh0,0*48

\c:1503079517*53\!AIVDM,2,2,9,A,00000000000,2*2D

\c:1503079516*52\!AIVDM,1,1,,A,13oP50Oi420UAtPgp@UPrP1d01,0*1A

\c:1503079516*52\!AIVDM,1,1,,B,B3mISo000H;wsB8SetMnww`5oP06,0*7C

\c:1503079517*53\!AIVDM,2,1,0,B,53aIjwh000010CSK7R04lu8F222222222222221?9@<297?o060@C51D`888,0*1B

A detailed breakdown of this format can be found on the NMEA website in their NMEA 0183 V4.00 presentation.