Does anyone know what the title translates to?

This is all I could find. Shimanami must be a name so there is no translation for that???

Shimanami nobody he; Shimane Tasogare

The manga takes place in Onomichi I think? http://www.mangago.zone/read-manga/shimanami_tasogare/mf/7f257e636a755e9e/Ch12/pg-5/ and Shimanami could be referring to a road that actually exists and people go cycling on it https://www.japan-guide.com/e/e3478.html

I looked up Tasogare, it relates to dusk/twilight somehow and something about the characters meaning "who is that person". I don't know any Japanese and my sources or my interpretation could be completely off on this.

Overall, No idea

Island Wave Dusk?

That's the best I could figure out. Shima = island , nami = wave , tasogare = dusk/twilight

There's a Shimanami bike course that goves over various islands. So, since this is set in that region, perhaps it's the idea of Twilight over the Island Waves?