Both Sirius & XM Satellite* radio are intended (and licenced) to provide service
to only North America.
Siruis utilizes inclined elliptical geosynchronous orbiting satellites, which provide a larger coverage area than XM’s geostationary satellites.
Neither system actually “turns off” their up-down link at the equator ~ the satellites just lose their line-of-site.
Notwithstanding, as currently configured, Sirius is generally available through Mexico
& Pueto Rico, while XM has an even smaller footprint. Both should be available in Bermuda
Radio Coverage Maps (Sirius left, XM right):