Good Advice Otto  - I remember coming back towards Akld City at night and a boat anchored up with no lights - back drop was so bright all I noticed was a dark hole - holy sh*t was a boat.  If I had hit it would have been expensive and traumatic for all involved (and I would have had an out as my lights were on).

 

would also add that a light is required when fishing at night.

number of times I've gone closer than I would normally past a boat fishing with no lights what-so-ever.

 

if you don't have a anchor light and fish at night then at least turn on a torch and shine it in the water and around you so as others will know your there.

so don't think ill bother

Solar garden lights are okay for the first few hours of darkness, especially if coming into a bay in the dark. But by 3a am to 4 am, they have run out of juice.....and those boats are at risk. 

Wefaknis, your boat is set up for cruising at night - one all round light and port and starboard lights. Funandfunction has it correct.

You need the all round white light on a separate circuit for use as an anchor light.

The maritime rule is; Anchor light; Every boat at anchor must show only a white light that is visible from all directions between sunset and sunrise.

The complete small boat lighting rules are;

 http://www.maritimenz.govt.nz/Publications-and-forms/Lookout/Issue-17-10.asp

As Otto said - YES! so some poor sod doesn't run into it at night. 

Anchor lights are best LEDs so the current draw is minimal when left on overnight. Not so critical (but nice) for nav lights as (generally) the engine will be running when they are on.

Not directed at you specifically MartinM  but thought others might benefit from knowing this:

A power driven vessel needs a steaming  light ( forward facing white light showing through 225 degrees, the same arc as the side lights). This is what differentiates it from the lights of a yacht.

If the vessel is less than 12m long , the steaming light can be combined with the stern light ( an aft facing white light with an arc of 235 degrees)  into one all round ( 360 degree ) white light.

 

In other words any small power vessel with legal nav lights   should already  have an all round white light that ,if it's separately switched , can then double as an anchor light.

 

If it was me , anchoring my boat in a bay at night I'd definitely leave a light on it and maybe look at a cheap solar panel if not doing enough motoring to keep the battery charge up.