Thanks for your answers....I think I'll go for the white flashlight...and
btw, in Switzerland, you apply the international rules, which means a
flashlight, at least...

For the emergency flare or lights, I carry 3 red flares (1 in the PFD and 2
on the boat) and a parachute flare. I will soon purchase a strobe but for
now I have a Photon 3 with SOS strobe...usefull only when weather conditions
are not too bad, of course
(http://www.photonlight.com/products/photon_3.html)

Another question, did everyone have a problem because of the lack of light
while navigating by night ?