A Wave is symbolized as one of the strongest forces on earth. so strength for one. also if you read more into it, its about faith, a wave is you against mother nature, you cannot control it, you just have to put your faith into her.
small geometric tattoo meanings - Google Search
44 Real-Girl Tiny Tattoo Ideas For Your First Ink: If you're a little nervous about a permanent stamp, the best way to start is with something small.