SOS
Electronic Visual Distress Signals (Panbo)
Sirius Signal (Weems & Plath) versus Orion, plus a new option
One LED Flare Replaces U.S. Required Pyros, Sirius Signal But Not Ocean Signal (BLOG)
Given that the cheapest flare set costs about $33 and expires 42 months after manufacturing, the Sirius substitute may be a "no brainer."