Forgive the idiot question but what is a strobe light at the mast head actually for? It certainly looks great but no doubt it has a particularly serious purpose!
If you put out a Mayday or Pan Pan, or other call for assistance, after dark, it will guide your rescuers to you. It could also warn large vessels if you think they haven't seen you and are getting rather close. Small vessel nav lights are difficult to see at anything other than close range.