I believe that a good selection of flares is the best way to attract
attention (assuming the other vessel has a proper watch 'on deck'.

I was once sinking in the middle of the night in Buzzards Bay. I was
pretty sure I could manage the situation and decided not to fire off
flares at the line of fishing vessels that were headed into New
Bedford. Then I realized that they were very likely to run me down
because the boat was small and I was pretty low in the water. I
decided to fire off a few flares. If they stopped, I'd ask them to
report me (no radio) and carry on.

I fired off my flares when I was right in front of them. They never
saw me.

--

Roger Long