dmaziuk
Contributor
I was using a $100 1,000 lumen light. An active light source flicked back and forth is apparently quite eye-catching.
Any XM-L LED should be able to pump out 1K actual(*) lumen(**), my $20 lights have 3 XM-L2s, so they are quite bright. That still doesn't convince me they'll be more (or less) eye-catching topside in bright Caribbean sunlight than the signal mirror.
Obviously, overcast, rain, no sun, yadda, yadda, yadda.
*) As opposed to Chinese lumens.
**) Whether a particular flashlight does or not is another question.