Unless I am very wrong indeed, a 406mhz beacon will work anywhere in the world. If you look up GMDSS the sea areas are divided into areas for distress alerting purposes. A 406Mhz is the gold standard, and will work anywhere. Alert times may be slightly longer due to the less frequent coverage by the LEOSAR sattelites, and the gaps in GEOSAR coverage. Nontheless 406mhz will be detected worldwide.
Potential confusion from the Imarsat service, which I believe is unreliable below approx 70 degrees South. I know the Australian and NZ SAR authorities reguarly deal with detects from well South of 70.
EWD