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.
family....finger tattoos are very are to do and the ink bleeds easily so make sure you find someone that actually know what they are doing most talented tattoo artists won't work with fingers. So if one says yes ask for pictures and do you're research.