From memory you need a constant white light - any red,green or flashing lights indicate that you're a vessel that's manoeuvrable enough to avoid a coming together. The white light effectively means you're stationary at anchor or moving slowly... At least in NSW.
Ive got one of these – been using it for a few months now a couple of times a week with plenty of offs and it's going strong. Casts a very visible light but doesn't illuminate much (if that makes sense) so won't ruin your night vision too much...:
www.anacondastores.com/fishing/terminal-tackle/lights-bellsJust two points to note:
1) Check the rubber fitting at the base for cracks, quite a few on the rack had serious cracks and would've failed pretty quickly i reckon.
2) if' it mounted on the rear deck don't fall backwards..