If I am not mistaken, this question has come up a few times before and no one, to my knowledge, has found a direct LED replacement for the anchor light. I have ordered a few that were "supposed" to fit, but had to send them back.
One way to save power while running an anchor light is to buy the Mega Utility Light from Davis Instruments, which only draws a tenth of an amp per hour, comes with a long cord and plugs into the 12 volt outlet. I have attached mine to a short piece of PVC which slides onto my radar arch-mounted VHF antenna, which gets it up over all of the stuff up there. We run the cord through the helm window.
This light can also be used in the cockpit by hanging it from the bimini. It works well and will do until I can find an LED replacement light for our anchor light.
Nick
"Valkyrie"