Question about dying my hair?

I have dark brown hair and it's bleached lighter in some parts and the color is kind of copper-ish in the bleached spots. If I want to dye my hair red in a burgundy shade, would I have to bleach the whole head first? I think so. But I just want to double check. I do plan on getting it done in a salon but with chlorine from the pool and the ocean will the color fade?