The wiring on Shaula needs some tidying up....
Specification of wire to be used for combined tricolor and anchor light at masthead
The light has 25W and 10W bulbs for tricolor and anchor lights respectively.
They should not be used together so the maximum power used should be 25W.
The round trip distance from the mast head to the switch panel is approx 100 feet
From ABYC tables we see that for 3% and 10% voltage drops we would therefore require 10 and 16 AWG wire.
Note that 10AWG = 2.6mm diam = 5.26mm2 area.
16AWG = 1.3mm diam = 1.3mm2 area.
We will need 3 core cable and therefore the core used for the anchor light is going to be greater capacity than actually required.
The cable will be exposed to the elements ie uv, heat , cold, hail stones etc at the top of the mast for about 1 meter
The cable should be tinned and Type III stranded (high winds will set up vibration of the mast head unit).
10AWG far too big to go up the mast!