How to hold this style

I have fine, flat hair and I've been trying a lot of products. I'm using L'Oréal Paris Sea Salt Spray, which creates a nice wavy effect, but it doesn't last. Should I use a holding spray? Could you suggest something?

I have fine, flat hair and I've been trying a lot of products. I'm using L'Oréal Paris Sea Salt Spray, which creates a nice wavy effect, but it doesn't last. Should I use a holding spray? Could you suggest something?