Starting next month the US coast guard only will receive distress calls in digital format, the guard said in a statement Thursday.

"Similar to the broadcasting world, which is transitioning from analog to digital frequencies, beginning February 1, the Coast Guard will only receive distress alert broadcasts from digital 406-MHz Emergency Position Indicating Radio Beacons," it said.

"The Coast Guard will no longer process analog signals transmitting on 121.5 or 243.0 MHz.

So "the Coast Guard urges mariners and aviators to upgrade their onboard analog equipment to include a digital 406-MHz EPIRB," it added.