I recently built this anchor light and it has been working well for me and I thought there may be others who may find this useful.
The attached picture shows the built light super glued to my flag pole (an old fishing rod) as well as all of the essential parts required to build the light. Note that to build the light you will require some basic electrical/electronic (soldering) skill.
The reasons I chose this type of light are: 12V, bright, cheap($3), long lasting and low energy consumption. I tested the light using my 1.3 Amp Hour battery and after 9 hours it was still going strong.
I purchased the light on ebay for $3 including shipping. The light is a "T10 White 5 SMD LED for Car Side Light / Headlight" and can be found (at the time of writing) at (http://www.ebay.com.au/itm/ws/eBayISAPI ... OC:AU:3160
The light globe is a plastic container that came in a travel set from The Reject Shop. The Coax-Seal and heat shrink tubing, from Jaycar, is used to form a holder for the bulb and and forms a water seal. The wire from the light connects to a 12V battery using a basic connecter.
Let me know if more details are required and I will be happy to provide additional information.
Disclaimer: I take no responsibility and assume no liability for any injury or damage arising from the use of this information.