as far as Canadian collison regulations go:
a powerboat under 12m (or a sailboat, whilst "steaming...") can display sidelights and one all-around white light - this can be at the top of the mast, or a combination of stern light and partial white light forward (usually referred to as steaming light **edit: and installed usually one-half to two-thirds way up a sailboat mast)
while sailing (vessel length 7-20m) - sidelights and stern light, or tricolour (**edit: at top of mast, or masthead)
so for simplicity's sake, one can get away with sidelights, one stern light, and a one 360 deg white light at top of the mast and cover off all scenarios.
for the extra effort of two more circuits, it's not a bad idea to add a combination steaming/deck light installed on the leading edge of the mast, (**around 2/3 the way up) you can turn on the "friday night lights" and makes it far easier to anchor and work on deck in the dark without having to hold a flashlight.......
on another sidenote about wiring sizes, don't forget that runs are cumulative, this doesn't always work in a bad way.... you can effectively lessen voltage drop by running larger wire where it's easy (inside the boat, ie 12ga panel to mast step) and then dropping down where its not quite so fun to work or not required (14ga, mast step to LED anchor light) instead of running 14 for the round trip, and being borderline on the run. buy (marine) wire from a wholesaler, by the roll, and you'll never again worry about cheaping out on an extra 6$ worth of wire and again ending with borderline runs
delcity is a great supplier, and you can buy listed wire (almo) and all sorts of other cabling, goodies, and tools from them. last i bought was about half the price of the ancor stuff...