Navigation General · Electronic Nav — AIS Classes
Compared with AIS Class A (carried by SOLAS vessels), AIS Class B units:
- ATransmit at higher power and priority
- BReplace radar entirely
- CTransmit less frequently at lower power and are typically voluntary on smaller craft✓ Correct
- DAre illegal in U.S. waters
Explanation
Class A (mandatory on SOLAS ships) transmits more data more often at higher power and has reporting priority. Class B is a simpler, lower-power, lower-rate unit used on smaller commercial and recreational vessels. Both share position, course, and speed.
Authority: ITU-R M.1371; 33 CFR Part 164
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