Depending on where you have it mounted, your anchor/all-around white light can be a pest when driving at night.
Mine is mounted slightly behind my driving position on the side deck of my boat.
I hate them mounted in front, or at the stern. Too much glare/reflected light.
I don't know if anyone else has come up with the same solution to night-time glare from the allround white light whilst driving the boat at night.
I bought a standard folding anchor light and extended the length of it by replacing the tubing.
Aluminium anodized tubing is available very cheaply from Bunnings in exactly the same size as original.
Just a matter of drilling out a single pop rivet in each end of the original fittings.
Then solder in some more wire as appropriate, and insulate well (Sealed with silicone and wrapped in electrical tape)
Measure sufficient length of tubing to clear the height of your bimini so your all-around white light can actually be seen from all-around.
Drill a hole in the side wall of the new tubing, pop in a rivet and your ready to mount and wire up.
The next step it took was to wrap black electrical tape around the white plastic screw-on shade for the light, at exactly the height of the filament in the globe, or a bee's-d!ck above it.
This prevents most of the light (directly from the filament) shining downward into the driver's eyes. Same for lighting up the foredeck - minimal.
It still allows white light out horizontally where other boats can see it.
A small amount of diffused light from the shade will still be reflected downwards, but not enough to bother your driving - well, not compared to the shade without tape anyhow.
The length of my tubing is approximately 1,100mm. This is enough height to clear the top of my bimini, without being too long.
All up cost if you already have the folding-type anchor light - Less than $10
Cheers, Sea-Dog