few suggestions for the bay window.

individual shades are one option. (woven woods, cellular, roman, solar, etc)

Another option is doing a window seat with cushion/pillows and having drapes pull across the whole thing. Or you can do individual shades.

BTW, instead of getting a useless blind for the transom window, why not do an insert of some type? stained glass, leaded glass, combo of both,,

,would be pretty.

would look something like this (I gave you a blue/green glass beachy design) with woven wood blinds and white drapes. (see below for more info on the window dressing)

You can design whatever you like (I have a link to the girl I used on Etsy if you like)

I did a stained glass insert over my own window in the bathroom. it's easy. held in place by clear silicone. you have the glass insert made to order to that windows dimesion.

Yours would be super easy since it's fixed. Mine opens and closes

here are examples to all of those

celluar shades w/a window bench

curtains w/window bench (BTW, these aren't difficult to DIY)

Roman shades

woven woods w/drapes for the bay

since you mentioned coastal, I really like this room, especially the beaded light. you have the height in your ceiling for something like this.

Love the board and batten panels behind the bed too. looks great w/the white textured rug and woven ratten elements.

Another way to do the batten panels. this is pretty easy. just run them up the entire wall. paint white and do the other walls in the seafoam (like shown here.)

Bring in the beaded light (or a fan) and try a sisal rug.

another coastal idea. roman shades on the window

Vertical panels behind the bed with a long shelf. put up beachy items to display

navy accent wall with white plantation shutters on the bay

another bay window (s) with linen style roman shades. love the woven rattan ceiling light, comfy chair by the window, potted plant.