Frim the point of a small boat sailor, the deck mounted lights are of limited value. Unless I specifically looking for one during the day, I won't see it. It will actually hide your silhouette if you're between me and the sun. The farthest I've detected 'yaks is if they're flying an orange flag on a 3-5 foot mast.

IMHO the best daytime visibility is a flag and high-vis jacket. The best nighttime is a mast mounted white or red/green/white light and a headlamp. If I see a strobe on the water, I'm going to assume somebody went overboard and will manuver for a pickup.

Flag/light/mast kits can be had for for $50-$100.