Because you have dark wood furniture, the first inspiration photos I'm posting have dark beds. Note that you can get the beach theme look without going 'overboard' ( sorry, pun). Anyway, you can paint the walls a pale blue or aqua and then add all white bedding and one throw and a pillow in a matching blue or aqua. Soft flowing drapes hung high in white will add to the feel. Just a few white framed photos or shells or ? will make for lovely wall decor. Also a sisal rug will add the 'sand' on the floor. You can also go with an all sand colored theme , as in the last photo. Pale beige walls, white soft drapes, beige and white bedding. It can be a classy look if done right.

In all of the above you could also consider painting your bedroom set white, but as you can see in the first photo, it will work if you keep the room serene and soft.

really some nice ideas

That is a fun piece. You can do that if you don't overdo the 'fish' idea in the rest of the room. There is that lovely aqua, teal and pale green in there too!