Masking outside curves with compound angles (ships bow)

I’ve been struggling to get this perfect for years, masking around the ships bow where two colors meet around the bow of a ship. Silly putty will not work btw. I use 1/2 inch masking tape and cut the profile but I always have to go back and re mask if only a little.

Its very noticeable on a 1/400 model of the QM2.

Any tips???