This site has a useful page on Marine AIS data format.

In using this page with AIS work, I've found what I think is a bug on the page which I'd like to contribute the fix to.

http://www.bosunsmate.org/ais/#bitvector

is the page section with the problem.

The problem is that the string given in the example: 14eG;o@034o8sd<L9i:a;WF>062D

Is supposed to correspond to the binary data given below it, only part of which I've shown here:

000001 000100 101101 010111 011100 001010 .....

The first 4 characters correspond, but 5th onward aren't right. E.g., the string's 5th character is ";", and the bit pattern for ";" given on this page:

http://catb.org/gpsd/AIVDM.html#_aivdm_aivdo_payload_armoring

Is supposed to be 001011, but in the example data above it is 011100, which should correspond to the letter "L".

The whole correction is just to change the string to this: 14eGL:@000o8oQ'LMjOchmG@08HK

That string matches the bits.
 

Thanks for noting this!

I haven't looked at that in a while but let me check into it!  I'll get it updated.