The design of an EPIRB has to be certified by the USCG, THEN granted a type approval by the FCC.
Take a look at this page: http://www.uscg.mil/hq/cg5/cg5214/epirbs.asp
You have quite a task ahead of you, and for starters the Arduino is NOT a radio transmitter, so I am not sure where you plan to make it fit in this project.
The necessary certification by a test facility recognized by one of the COSPAS/SARSAT Partners will run you an easy five-figure sum by itself.
All things considered, I would have to rate the feasibility as very poor.