Did you want want the light bulb? or the entire unit?
Light bulb is a fastoon: Mfg # 0071DP0CLR
You can get genuine replacements: here.
Be sure to measure and see if it is the correct one: 12 Volts, 10 watts, Diameter: 3/8" Length: 1 1/8". You can also get replacement LED bulbs. Always carry spare bulbs for incandescent running lights. I also carry a battery operated dinghy light--and if I had loss of my running lights--I could use these in a extreme situation.