You'd ideally want straight up & down or vertical for the BOW lights to give true coverage in the 'same plane' of the hull and/or to the water surface from 8 o'cock on the port and up/around past 12 (bow or ahead) over to 4 o'clock on the starboard (per ColRegs). For base shape, use what fits the gunnel best.
The raked or angle mount can be used on the 'all around' or stern light - as that is intended to just throw a 360 -pattern and the 'plane of view' doesn't really matter as much and many stern lights have an angle adjustment right below the lamp anyway.
TIP - What I do with the stern lights. Know how they have a friction-fit collar that tightens the post into the base? I carefully cut off the base of the light post, preserving the wires, i.e., without knicking or cutting into them. Then I turn the base over and cut off the base. Now the light post will slide all the way down into the base, like a 12" or 18" light post that will collapse all the way down into your hull or inside the gunnel (depending of course on YOUR hull layout and depth).
I wire the stern light with the post out of the base, using good marine butt connectors and adhesive-lined heatshrink. Then I simply put the light post into the base and put it all the way down - when not in use & OFF - or extended up when in use & ON.
Advantages (to me anyway): The light is always wired and ready for instant use and by collapsing, it stays
relatively out of the way of everything. And most important, the wiring stays integral and is reliable (make sure though, there is space below the gunnel mount for it to 'coil' when collapsed).
I hated having to go find the stern light to use it and then at least when on
other people's boats, the connections on the base of the light post or the base itself, or both, were always sooooooooo corroded that they never worked anyway! To me, my solution solved all those issues!
But I readily admit that I do boat a lot in low light and/or dark conditions.
