Effective from 1st January 2012, Singapore has extended to private visiting yachts, the requirement that all vessels entering Singapore waters have on board a class A or class B AIS transponder.
Previously, the AIS requirement did not apply to private visiting vessels. It is advisable not to ignore this new rule as the Singapore Authorities generally apply their regulations very seriously. As this is a new requirement there maybe some leeway but it would be wise not to rely on it.
Info from Noonsite: